Created starter files for the project.

venv/Lib/site-packages/pip/_vendor/requests/__init__.py

@@ -0,0 +1,144 @@
+# -*- coding: utf-8 -*-
+
+#   __
+#  /__)  _  _     _   _ _/   _
+# / (   (- (/ (/ (- _)  /  _)
+#          /
+
+"""
+Requests HTTP Library
+~~~~~~~~~~~~~~~~~~~~~
+
+Requests is an HTTP library, written in Python, for human beings.
+Basic GET usage:
+
+   >>> import requests
+   >>> r = requests.get('https://www.python.org')
+   >>> r.status_code
+   200
+   >>> b'Python is a programming language' in r.content
+   True
+
+... or POST:
+
+   >>> payload = dict(key1='value1', key2='value2')
+   >>> r = requests.post('https://httpbin.org/post', data=payload)
+   >>> print(r.text)
+   {
+     ...
+     "form": {
+       "key1": "value1",
+       "key2": "value2"
+     },
+     ...
+   }
+
+The other HTTP methods are supported - see `requests.api`. Full documentation
+is at <https://requests.readthedocs.io>.
+
+:copyright: (c) 2017 by Kenneth Reitz.
+:license: Apache 2.0, see LICENSE for more details.
+"""
+
+from pip._vendor import urllib3
+from pip._vendor import chardet
+import warnings
+from .exceptions import RequestsDependencyWarning
+
+
+def check_compatibility(urllib3_version, chardet_version):
+    urllib3_version = urllib3_version.split('.')
+    assert urllib3_version != ['dev']  # Verify urllib3 isn't installed from git.
+
+    # Sometimes, urllib3 only reports its version as 16.1.
+    if len(urllib3_version) == 2:
+        urllib3_version.append('0')
+
+    # Check urllib3 for compatibility.
+    major, minor, patch = urllib3_version  # noqa: F811
+    major, minor, patch = int(major), int(minor), int(patch)
+    # urllib3 >= 1.21.1, <= 1.25
+    assert major == 1
+    assert minor >= 21
+    assert minor <= 25
+
+    # Check chardet for compatibility.
+    major, minor, patch = chardet_version.split('.')[:3]
+    major, minor, patch = int(major), int(minor), int(patch)
+    # chardet >= 3.0.2, < 3.1.0
+    assert major == 3
+    assert minor < 1
+    assert patch >= 2
+
+
+def _check_cryptography(cryptography_version):
+    # cryptography < 1.3.4
+    try:
+        cryptography_version = list(map(int, cryptography_version.split('.')))
+    except ValueError:
+        return
+
+    if cryptography_version < [1, 3, 4]:
+        warning = 'Old version of cryptography ({}) may cause slowdown.'.format(cryptography_version)
+        warnings.warn(warning, RequestsDependencyWarning)
+
+# Check imported dependencies for compatibility.
+try:
+    check_compatibility(urllib3.__version__, chardet.__version__)
+except (AssertionError, ValueError):
+    warnings.warn("urllib3 ({}) or chardet ({}) doesn't match a supported "
+                  "version!".format(urllib3.__version__, chardet.__version__),
+                  RequestsDependencyWarning)
+
+# Attempt to enable urllib3's fallback for SNI support
+# if the standard library doesn't support SNI or the
+# 'ssl' library isn't available.
+try:
+    # Note: This logic prevents upgrading cryptography on Windows, if imported
+    #       as part of pip.
+    from pip._internal.utils.compat import WINDOWS
+    if not WINDOWS:
+        raise ImportError("pip internals: don't import cryptography on Windows")
+    try:
+        import ssl
+    except ImportError:
+        ssl = None
+
+    if not getattr(ssl, "HAS_SNI", False):
+        from pip._vendor.urllib3.contrib import pyopenssl
+        pyopenssl.inject_into_urllib3()
+
+        # Check cryptography version
+        from cryptography import __version__ as cryptography_version
+        _check_cryptography(cryptography_version)
+except ImportError:
+    pass
+
+# urllib3's DependencyWarnings should be silenced.
+from pip._vendor.urllib3.exceptions import DependencyWarning
+warnings.simplefilter('ignore', DependencyWarning)
+
+from .__version__ import __title__, __description__, __url__, __version__
+from .__version__ import __build__, __author__, __author_email__, __license__
+from .__version__ import __copyright__, __cake__
+
+from . import utils
+from . import packages
+from .models import Request, Response, PreparedRequest
+from .api import request, get, head, post, patch, put, delete, options
+from .sessions import session, Session
+from .status_codes import codes
+from .exceptions import (
+    RequestException, Timeout, URLRequired,
+    TooManyRedirects, HTTPError, ConnectionError,
+    FileModeWarning, ConnectTimeout, ReadTimeout
+)
+
+# Set default logging handler to avoid "No handler found" warnings.
+import logging
+from logging import NullHandler
+
+logging.getLogger(__name__).addHandler(NullHandler())
+
+# FileModeWarnings go off per the default.
+warnings.simplefilter('default', FileModeWarning, append=True)

venv/Lib/site-packages/pip/_vendor/requests/__version__.py

@@ -0,0 +1,14 @@
+# .-. .-. .-. . . .-. .-. .-. .-.
+# |(  |-  |.| | | |-  `-.  |  `-.
+# ' ' `-' `-`.`-' `-' `-'  '  `-'
+
+__title__ = 'requests'
+__description__ = 'Python HTTP for Humans.'
+__url__ = 'https://requests.readthedocs.io'
+__version__ = '2.24.0'
+__build__ = 0x022400
+__author__ = 'Kenneth Reitz'
+__author_email__ = 'me@kennethreitz.org'
+__license__ = 'Apache 2.0'
+__copyright__ = 'Copyright 2020 Kenneth Reitz'
+__cake__ = u'\u2728 \U0001f370 \u2728'

venv/Lib/site-packages/pip/_vendor/requests/_internal_utils.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests._internal_utils
+~~~~~~~~~~~~~~
+
+Provides utility functions that are consumed internally by Requests
+which depend on extremely few external helpers (such as compat)
+"""
+
+from .compat import is_py2, builtin_str, str
+
+
+def to_native_string(string, encoding='ascii'):
+    """Given a string object, regardless of type, returns a representation of
+    that string in the native string type, encoding and decoding where
+    necessary. This assumes ASCII unless told otherwise.
+    """
+    if isinstance(string, builtin_str):
+        out = string
+    else:
+        if is_py2:
+            out = string.encode(encoding)
+        else:
+            out = string.decode(encoding)
+
+    return out
+
+
+def unicode_is_ascii(u_string):
+    """Determine if unicode string only contains ASCII characters.
+
+    :param str u_string: unicode string to check. Must be unicode
+        and not Python 2 `str`.
+    :rtype: bool
+    """
+    assert isinstance(u_string, str)
+    try:
+        u_string.encode('ascii')
+        return True
+    except UnicodeEncodeError:
+        return False

venv/Lib/site-packages/pip/_vendor/requests/adapters.py

@@ -0,0 +1,533 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.adapters
+~~~~~~~~~~~~~~~~~
+
+This module contains the transport adapters that Requests uses to define
+and maintain connections.
+"""
+
+import os.path
+import socket
+
+from pip._vendor.urllib3.poolmanager import PoolManager, proxy_from_url
+from pip._vendor.urllib3.response import HTTPResponse
+from pip._vendor.urllib3.util import parse_url
+from pip._vendor.urllib3.util import Timeout as TimeoutSauce
+from pip._vendor.urllib3.util.retry import Retry
+from pip._vendor.urllib3.exceptions import ClosedPoolError
+from pip._vendor.urllib3.exceptions import ConnectTimeoutError
+from pip._vendor.urllib3.exceptions import HTTPError as _HTTPError
+from pip._vendor.urllib3.exceptions import MaxRetryError
+from pip._vendor.urllib3.exceptions import NewConnectionError
+from pip._vendor.urllib3.exceptions import ProxyError as _ProxyError
+from pip._vendor.urllib3.exceptions import ProtocolError
+from pip._vendor.urllib3.exceptions import ReadTimeoutError
+from pip._vendor.urllib3.exceptions import SSLError as _SSLError
+from pip._vendor.urllib3.exceptions import ResponseError
+from pip._vendor.urllib3.exceptions import LocationValueError
+
+from .models import Response
+from .compat import urlparse, basestring
+from .utils import (DEFAULT_CA_BUNDLE_PATH, extract_zipped_paths,
+                    get_encoding_from_headers, prepend_scheme_if_needed,
+                    get_auth_from_url, urldefragauth, select_proxy)
+from .structures import CaseInsensitiveDict
+from .cookies import extract_cookies_to_jar
+from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError,
+                         ProxyError, RetryError, InvalidSchema, InvalidProxyURL,
+                         InvalidURL)
+from .auth import _basic_auth_str
+
+try:
+    from pip._vendor.urllib3.contrib.socks import SOCKSProxyManager
+except ImportError:
+    def SOCKSProxyManager(*args, **kwargs):
+        raise InvalidSchema("Missing dependencies for SOCKS support.")
+
+DEFAULT_POOLBLOCK = False
+DEFAULT_POOLSIZE = 10
+DEFAULT_RETRIES = 0
+DEFAULT_POOL_TIMEOUT = None
+
+
+class BaseAdapter(object):
+    """The Base Transport Adapter"""
+
+    def __init__(self):
+        super(BaseAdapter, self).__init__()
+
+    def send(self, request, stream=False, timeout=None, verify=True,
+             cert=None, proxies=None):
+        """Sends PreparedRequest object. Returns Response object.
+
+        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
+        :param stream: (optional) Whether to stream the request content.
+        :param timeout: (optional) How long to wait for the server to send
+            data before giving up, as a float, or a :ref:`(connect timeout,
+            read timeout) <timeouts>` tuple.
+        :type timeout: float or tuple
+        :param verify: (optional) Either a boolean, in which case it controls whether we verify
+            the server's TLS certificate, or a string, in which case it must be a path
+            to a CA bundle to use
+        :param cert: (optional) Any user-provided SSL certificate to be trusted.
+        :param proxies: (optional) The proxies dictionary to apply to the request.
+        """
+        raise NotImplementedError
+
+    def close(self):
+        """Cleans up adapter specific items."""
+        raise NotImplementedError
+
+
+class HTTPAdapter(BaseAdapter):
+    """The built-in HTTP Adapter for urllib3.
+
+    Provides a general-case interface for Requests sessions to contact HTTP and
+    HTTPS urls by implementing the Transport Adapter interface. This class will
+    usually be created by the :class:`Session <Session>` class under the
+    covers.
+
+    :param pool_connections: The number of urllib3 connection pools to cache.
+    :param pool_maxsize: The maximum number of connections to save in the pool.
+    :param max_retries: The maximum number of retries each connection
+        should attempt. Note, this applies only to failed DNS lookups, socket
+        connections and connection timeouts, never to requests where data has
+        made it to the server. By default, Requests does not retry failed
+        connections. If you need granular control over the conditions under
+        which we retry a request, import urllib3's ``Retry`` class and pass
+        that instead.
+    :param pool_block: Whether the connection pool should block for connections.
+
+    Usage::
+
+      >>> import requests
+      >>> s = requests.Session()
+      >>> a = requests.adapters.HTTPAdapter(max_retries=3)
+      >>> s.mount('http://', a)
+    """
+    __attrs__ = ['max_retries', 'config', '_pool_connections', '_pool_maxsize',
+                 '_pool_block']
+
+    def __init__(self, pool_connections=DEFAULT_POOLSIZE,
+                 pool_maxsize=DEFAULT_POOLSIZE, max_retries=DEFAULT_RETRIES,
+                 pool_block=DEFAULT_POOLBLOCK):
+        if max_retries == DEFAULT_RETRIES:
+            self.max_retries = Retry(0, read=False)
+        else:
+            self.max_retries = Retry.from_int(max_retries)
+        self.config = {}
+        self.proxy_manager = {}
+
+        super(HTTPAdapter, self).__init__()
+
+        self._pool_connections = pool_connections
+        self._pool_maxsize = pool_maxsize
+        self._pool_block = pool_block
+
+        self.init_poolmanager(pool_connections, pool_maxsize, block=pool_block)
+
+    def __getstate__(self):
+        return {attr: getattr(self, attr, None) for attr in self.__attrs__}
+
+    def __setstate__(self, state):
+        # Can't handle by adding 'proxy_manager' to self.__attrs__ because
+        # self.poolmanager uses a lambda function, which isn't pickleable.
+        self.proxy_manager = {}
+        self.config = {}
+
+        for attr, value in state.items():
+            setattr(self, attr, value)
+
+        self.init_poolmanager(self._pool_connections, self._pool_maxsize,
+                              block=self._pool_block)
+
+    def init_poolmanager(self, connections, maxsize, block=DEFAULT_POOLBLOCK, **pool_kwargs):
+        """Initializes a urllib3 PoolManager.
+
+        This method should not be called from user code, and is only
+        exposed for use when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param connections: The number of urllib3 connection pools to cache.
+        :param maxsize: The maximum number of connections to save in the pool.
+        :param block: Block when no free connections are available.
+        :param pool_kwargs: Extra keyword arguments used to initialize the Pool Manager.
+        """
+        # save these values for pickling
+        self._pool_connections = connections
+        self._pool_maxsize = maxsize
+        self._pool_block = block
+
+        self.poolmanager = PoolManager(num_pools=connections, maxsize=maxsize,
+                                       block=block, strict=True, **pool_kwargs)
+
+    def proxy_manager_for(self, proxy, **proxy_kwargs):
+        """Return urllib3 ProxyManager for the given proxy.
+
+        This method should not be called from user code, and is only
+        exposed for use when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param proxy: The proxy to return a urllib3 ProxyManager for.
+        :param proxy_kwargs: Extra keyword arguments used to configure the Proxy Manager.
+        :returns: ProxyManager
+        :rtype: urllib3.ProxyManager
+        """
+        if proxy in self.proxy_manager:
+            manager = self.proxy_manager[proxy]
+        elif proxy.lower().startswith('socks'):
+            username, password = get_auth_from_url(proxy)
+            manager = self.proxy_manager[proxy] = SOCKSProxyManager(
+                proxy,
+                username=username,
+                password=password,
+                num_pools=self._pool_connections,
+                maxsize=self._pool_maxsize,
+                block=self._pool_block,
+                **proxy_kwargs
+            )
+        else:
+            proxy_headers = self.proxy_headers(proxy)
+            manager = self.proxy_manager[proxy] = proxy_from_url(
+                proxy,
+                proxy_headers=proxy_headers,
+                num_pools=self._pool_connections,
+                maxsize=self._pool_maxsize,
+                block=self._pool_block,
+                **proxy_kwargs)
+
+        return manager
+
+    def cert_verify(self, conn, url, verify, cert):
+        """Verify a SSL certificate. This method should not be called from user
+        code, and is only exposed for use when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param conn: The urllib3 connection object associated with the cert.
+        :param url: The requested URL.
+        :param verify: Either a boolean, in which case it controls whether we verify
+            the server's TLS certificate, or a string, in which case it must be a path
+            to a CA bundle to use
+        :param cert: The SSL certificate to verify.
+        """
+        if url.lower().startswith('https') and verify:
+
+            cert_loc = None
+
+            # Allow self-specified cert location.
+            if verify is not True:
+                cert_loc = verify
+
+            if not cert_loc:
+                cert_loc = extract_zipped_paths(DEFAULT_CA_BUNDLE_PATH)
+
+            if not cert_loc or not os.path.exists(cert_loc):
+                raise IOError("Could not find a suitable TLS CA certificate bundle, "
+                              "invalid path: {}".format(cert_loc))
+
+            conn.cert_reqs = 'CERT_REQUIRED'
+
+            if not os.path.isdir(cert_loc):
+                conn.ca_certs = cert_loc
+            else:
+                conn.ca_cert_dir = cert_loc
+        else:
+            conn.cert_reqs = 'CERT_NONE'
+            conn.ca_certs = None
+            conn.ca_cert_dir = None
+
+        if cert:
+            if not isinstance(cert, basestring):
+                conn.cert_file = cert[0]
+                conn.key_file = cert[1]
+            else:
+                conn.cert_file = cert
+                conn.key_file = None
+            if conn.cert_file and not os.path.exists(conn.cert_file):
+                raise IOError("Could not find the TLS certificate file, "
+                              "invalid path: {}".format(conn.cert_file))
+            if conn.key_file and not os.path.exists(conn.key_file):
+                raise IOError("Could not find the TLS key file, "
+                              "invalid path: {}".format(conn.key_file))
+
+    def build_response(self, req, resp):
+        """Builds a :class:`Response <requests.Response>` object from a urllib3
+        response. This should not be called from user code, and is only exposed
+        for use when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`
+
+        :param req: The :class:`PreparedRequest <PreparedRequest>` used to generate the response.
+        :param resp: The urllib3 response object.
+        :rtype: requests.Response
+        """
+        response = Response()
+
+        # Fallback to None if there's no status_code, for whatever reason.
+        response.status_code = getattr(resp, 'status', None)
+
+        # Make headers case-insensitive.
+        response.headers = CaseInsensitiveDict(getattr(resp, 'headers', {}))
+
+        # Set encoding.
+        response.encoding = get_encoding_from_headers(response.headers)
+        response.raw = resp
+        response.reason = response.raw.reason
+
+        if isinstance(req.url, bytes):
+            response.url = req.url.decode('utf-8')
+        else:
+            response.url = req.url
+
+        # Add new cookies from the server.
+        extract_cookies_to_jar(response.cookies, req, resp)
+
+        # Give the Response some context.
+        response.request = req
+        response.connection = self
+
+        return response
+
+    def get_connection(self, url, proxies=None):
+        """Returns a urllib3 connection for the given URL. This should not be
+        called from user code, and is only exposed for use when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param url: The URL to connect to.
+        :param proxies: (optional) A Requests-style dictionary of proxies used on this request.
+        :rtype: urllib3.ConnectionPool
+        """
+        proxy = select_proxy(url, proxies)
+
+        if proxy:
+            proxy = prepend_scheme_if_needed(proxy, 'http')
+            proxy_url = parse_url(proxy)
+            if not proxy_url.host:
+                raise InvalidProxyURL("Please check proxy URL. It is malformed"
+                                      " and could be missing the host.")
+            proxy_manager = self.proxy_manager_for(proxy)
+            conn = proxy_manager.connection_from_url(url)
+        else:
+            # Only scheme should be lower case
+            parsed = urlparse(url)
+            url = parsed.geturl()
+            conn = self.poolmanager.connection_from_url(url)
+
+        return conn
+
+    def close(self):
+        """Disposes of any internal state.
+
+        Currently, this closes the PoolManager and any active ProxyManager,
+        which closes any pooled connections.
+        """
+        self.poolmanager.clear()
+        for proxy in self.proxy_manager.values():
+            proxy.clear()
+
+    def request_url(self, request, proxies):
+        """Obtain the url to use when making the final request.
+
+        If the message is being sent through a HTTP proxy, the full URL has to
+        be used. Otherwise, we should only use the path portion of the URL.
+
+        This should not be called from user code, and is only exposed for use
+        when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
+        :param proxies: A dictionary of schemes or schemes and hosts to proxy URLs.
+        :rtype: str
+        """
+        proxy = select_proxy(request.url, proxies)
+        scheme = urlparse(request.url).scheme
+
+        is_proxied_http_request = (proxy and scheme != 'https')
+        using_socks_proxy = False
+        if proxy:
+            proxy_scheme = urlparse(proxy).scheme.lower()
+            using_socks_proxy = proxy_scheme.startswith('socks')
+
+        url = request.path_url
+        if is_proxied_http_request and not using_socks_proxy:
+            url = urldefragauth(request.url)
+
+        return url
+
+    def add_headers(self, request, **kwargs):
+        """Add any headers needed by the connection. As of v2.0 this does
+        nothing by default, but is left for overriding by users that subclass
+        the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        This should not be called from user code, and is only exposed for use
+        when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param request: The :class:`PreparedRequest <PreparedRequest>` to add headers to.
+        :param kwargs: The keyword arguments from the call to send().
+        """
+        pass
+
+    def proxy_headers(self, proxy):
+        """Returns a dictionary of the headers to add to any request sent
+        through a proxy. This works with urllib3 magic to ensure that they are
+        correctly sent to the proxy, rather than in a tunnelled request if
+        CONNECT is being used.
+
+        This should not be called from user code, and is only exposed for use
+        when subclassing the
+        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.
+
+        :param proxy: The url of the proxy being used for this request.
+        :rtype: dict
+        """
+        headers = {}
+        username, password = get_auth_from_url(proxy)
+
+        if username:
+            headers['Proxy-Authorization'] = _basic_auth_str(username,
+                                                             password)
+
+        return headers
+
+    def send(self, request, stream=False, timeout=None, verify=True, cert=None, proxies=None):
+        """Sends PreparedRequest object. Returns Response object.
+
+        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
+        :param stream: (optional) Whether to stream the request content.
+        :param timeout: (optional) How long to wait for the server to send
+            data before giving up, as a float, or a :ref:`(connect timeout,
+            read timeout) <timeouts>` tuple.
+        :type timeout: float or tuple or urllib3 Timeout object
+        :param verify: (optional) Either a boolean, in which case it controls whether
+            we verify the server's TLS certificate, or a string, in which case it
+            must be a path to a CA bundle to use
+        :param cert: (optional) Any user-provided SSL certificate to be trusted.
+        :param proxies: (optional) The proxies dictionary to apply to the request.
+        :rtype: requests.Response
+        """
+
+        try:
+            conn = self.get_connection(request.url, proxies)
+        except LocationValueError as e:
+            raise InvalidURL(e, request=request)
+
+        self.cert_verify(conn, request.url, verify, cert)
+        url = self.request_url(request, proxies)
+        self.add_headers(request, stream=stream, timeout=timeout, verify=verify, cert=cert, proxies=proxies)
+
+        chunked = not (request.body is None or 'Content-Length' in request.headers)
+
+        if isinstance(timeout, tuple):
+            try:
+                connect, read = timeout
+                timeout = TimeoutSauce(connect=connect, read=read)
+            except ValueError as e:
+                # this may raise a string formatting error.
+                err = ("Invalid timeout {}. Pass a (connect, read) "
+                       "timeout tuple, or a single float to set "
+                       "both timeouts to the same value".format(timeout))
+                raise ValueError(err)
+        elif isinstance(timeout, TimeoutSauce):
+            pass
+        else:
+            timeout = TimeoutSauce(connect=timeout, read=timeout)
+
+        try:
+            if not chunked:
+                resp = conn.urlopen(
+                    method=request.method,
+                    url=url,
+                    body=request.body,
+                    headers=request.headers,
+                    redirect=False,
+                    assert_same_host=False,
+                    preload_content=False,
+                    decode_content=False,
+                    retries=self.max_retries,
+                    timeout=timeout
+                )
+
+            # Send the request.
+            else:
+                if hasattr(conn, 'proxy_pool'):
+                    conn = conn.proxy_pool
+
+                low_conn = conn._get_conn(timeout=DEFAULT_POOL_TIMEOUT)
+
+                try:
+                    low_conn.putrequest(request.method,
+                                        url,
+                                        skip_accept_encoding=True)
+
+                    for header, value in request.headers.items():
+                        low_conn.putheader(header, value)
+
+                    low_conn.endheaders()
+
+                    for i in request.body:
+                        low_conn.send(hex(len(i))[2:].encode('utf-8'))
+                        low_conn.send(b'\r\n')
+                        low_conn.send(i)
+                        low_conn.send(b'\r\n')
+                    low_conn.send(b'0\r\n\r\n')
+
+                    # Receive the response from the server
+                    try:
+                        # For Python 2.7, use buffering of HTTP responses
+                        r = low_conn.getresponse(buffering=True)
+                    except TypeError:
+                        # For compatibility with Python 3.3+
+                        r = low_conn.getresponse()
+
+                    resp = HTTPResponse.from_httplib(
+                        r,
+                        pool=conn,
+                        connection=low_conn,
+                        preload_content=False,
+                        decode_content=False
+                    )
+                except:
+                    # If we hit any problems here, clean up the connection.
+                    # Then, reraise so that we can handle the actual exception.
+                    low_conn.close()
+                    raise
+
+        except (ProtocolError, socket.error) as err:
+            raise ConnectionError(err, request=request)
+
+        except MaxRetryError as e:
+            if isinstance(e.reason, ConnectTimeoutError):
+                # TODO: Remove this in 3.0.0: see #2811
+                if not isinstance(e.reason, NewConnectionError):
+                    raise ConnectTimeout(e, request=request)
+
+            if isinstance(e.reason, ResponseError):
+                raise RetryError(e, request=request)
+
+            if isinstance(e.reason, _ProxyError):
+                raise ProxyError(e, request=request)
+
+            if isinstance(e.reason, _SSLError):
+                # This branch is for urllib3 v1.22 and later.
+                raise SSLError(e, request=request)
+
+            raise ConnectionError(e, request=request)
+
+        except ClosedPoolError as e:
+            raise ConnectionError(e, request=request)
+
+        except _ProxyError as e:
+            raise ProxyError(e)
+
+        except (_SSLError, _HTTPError) as e:
+            if isinstance(e, _SSLError):
+                # This branch is for urllib3 versions earlier than v1.22
+                raise SSLError(e, request=request)
+            elif isinstance(e, ReadTimeoutError):
+                raise ReadTimeout(e, request=request)
+            else:
+                raise
+
+        return self.build_response(request, resp)

venv/Lib/site-packages/pip/_vendor/requests/api.py

@@ -0,0 +1,161 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.api
+~~~~~~~~~~~~
+
+This module implements the Requests API.
+
+:copyright: (c) 2012 by Kenneth Reitz.
+:license: Apache2, see LICENSE for more details.
+"""
+
+from . import sessions
+
+
+def request(method, url, **kwargs):
+    """Constructs and sends a :class:`Request <Request>`.
+
+    :param method: method for the new :class:`Request` object: ``GET``, ``OPTIONS``, ``HEAD``, ``POST``, ``PUT``, ``PATCH``, or ``DELETE``.
+    :param url: URL for the new :class:`Request` object.
+    :param params: (optional) Dictionary, list of tuples or bytes to send
+        in the query string for the :class:`Request`.
+    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+        object to send in the body of the :class:`Request`.
+    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
+    :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
+    :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
+    :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
+        ``file-tuple`` can be a 2-tuple ``('filename', fileobj)``, 3-tuple ``('filename', fileobj, 'content_type')``
+        or a 4-tuple ``('filename', fileobj, 'content_type', custom_headers)``, where ``'content-type'`` is a string
+        defining the content type of the given file and ``custom_headers`` a dict-like object containing additional headers
+        to add for the file.
+    :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
+    :param timeout: (optional) How many seconds to wait for the server to send data
+        before giving up, as a float, or a :ref:`(connect timeout, read
+        timeout) <timeouts>` tuple.
+    :type timeout: float or tuple
+    :param allow_redirects: (optional) Boolean. Enable/disable GET/OPTIONS/POST/PUT/PATCH/DELETE/HEAD redirection. Defaults to ``True``.
+    :type allow_redirects: bool
+    :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
+    :param verify: (optional) Either a boolean, in which case it controls whether we verify
+            the server's TLS certificate, or a string, in which case it must be a path
+            to a CA bundle to use. Defaults to ``True``.
+    :param stream: (optional) if ``False``, the response content will be immediately downloaded.
+    :param cert: (optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+
+    Usage::
+
+      >>> import requests
+      >>> req = requests.request('GET', 'https://httpbin.org/get')
+      >>> req
+      <Response [200]>
+    """
+
+    # By using the 'with' statement we are sure the session is closed, thus we
+    # avoid leaving sockets open which can trigger a ResourceWarning in some
+    # cases, and look like a memory leak in others.
+    with sessions.Session() as session:
+        return session.request(method=method, url=url, **kwargs)
+
+
+def get(url, params=None, **kwargs):
+    r"""Sends a GET request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param params: (optional) Dictionary, list of tuples or bytes to send
+        in the query string for the :class:`Request`.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    kwargs.setdefault('allow_redirects', True)
+    return request('get', url, params=params, **kwargs)
+
+
+def options(url, **kwargs):
+    r"""Sends an OPTIONS request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    kwargs.setdefault('allow_redirects', True)
+    return request('options', url, **kwargs)
+
+
+def head(url, **kwargs):
+    r"""Sends a HEAD request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param \*\*kwargs: Optional arguments that ``request`` takes. If
+        `allow_redirects` is not provided, it will be set to `False` (as
+        opposed to the default :meth:`request` behavior).
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    kwargs.setdefault('allow_redirects', False)
+    return request('head', url, **kwargs)
+
+
+def post(url, data=None, json=None, **kwargs):
+    r"""Sends a POST request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+        object to send in the body of the :class:`Request`.
+    :param json: (optional) json data to send in the body of the :class:`Request`.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    return request('post', url, data=data, json=json, **kwargs)
+
+
+def put(url, data=None, **kwargs):
+    r"""Sends a PUT request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+        object to send in the body of the :class:`Request`.
+    :param json: (optional) json data to send in the body of the :class:`Request`.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    return request('put', url, data=data, **kwargs)
+
+
+def patch(url, data=None, **kwargs):
+    r"""Sends a PATCH request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+        object to send in the body of the :class:`Request`.
+    :param json: (optional) json data to send in the body of the :class:`Request`.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    return request('patch', url, data=data, **kwargs)
+
+
+def delete(url, **kwargs):
+    r"""Sends a DELETE request.
+
+    :param url: URL for the new :class:`Request` object.
+    :param \*\*kwargs: Optional arguments that ``request`` takes.
+    :return: :class:`Response <Response>` object
+    :rtype: requests.Response
+    """
+
+    return request('delete', url, **kwargs)

venv/Lib/site-packages/pip/_vendor/requests/auth.py

@@ -0,0 +1,305 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.auth
+~~~~~~~~~~~~~
+
+This module contains the authentication handlers for Requests.
+"""
+
+import os
+import re
+import time
+import hashlib
+import threading
+import warnings
+
+from base64 import b64encode
+
+from .compat import urlparse, str, basestring
+from .cookies import extract_cookies_to_jar
+from ._internal_utils import to_native_string
+from .utils import parse_dict_header
+
+CONTENT_TYPE_FORM_URLENCODED = 'application/x-www-form-urlencoded'
+CONTENT_TYPE_MULTI_PART = 'multipart/form-data'
+
+
+def _basic_auth_str(username, password):
+    """Returns a Basic Auth string."""
+
+    # "I want us to put a big-ol' comment on top of it that
+    # says that this behaviour is dumb but we need to preserve
+    # it because people are relying on it."
+    #    - Lukasa
+    #
+    # These are here solely to maintain backwards compatibility
+    # for things like ints. This will be removed in 3.0.0.
+    if not isinstance(username, basestring):
+        warnings.warn(
+            "Non-string usernames will no longer be supported in Requests "
+            "3.0.0. Please convert the object you've passed in ({!r}) to "
+            "a string or bytes object in the near future to avoid "
+            "problems.".format(username),
+            category=DeprecationWarning,
+        )
+        username = str(username)
+
+    if not isinstance(password, basestring):
+        warnings.warn(
+            "Non-string passwords will no longer be supported in Requests "
+            "3.0.0. Please convert the object you've passed in ({!r}) to "
+            "a string or bytes object in the near future to avoid "
+            "problems.".format(type(password)),
+            category=DeprecationWarning,
+        )
+        password = str(password)
+    # -- End Removal --
+
+    if isinstance(username, str):
+        username = username.encode('latin1')
+
+    if isinstance(password, str):
+        password = password.encode('latin1')
+
+    authstr = 'Basic ' + to_native_string(
+        b64encode(b':'.join((username, password))).strip()
+    )
+
+    return authstr
+
+
+class AuthBase(object):
+    """Base class that all auth implementations derive from"""
+
+    def __call__(self, r):
+        raise NotImplementedError('Auth hooks must be callable.')
+
+
+class HTTPBasicAuth(AuthBase):
+    """Attaches HTTP Basic Authentication to the given Request object."""
+
+    def __init__(self, username, password):
+        self.username = username
+        self.password = password
+
+    def __eq__(self, other):
+        return all([
+            self.username == getattr(other, 'username', None),
+            self.password == getattr(other, 'password', None)
+        ])
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __call__(self, r):
+        r.headers['Authorization'] = _basic_auth_str(self.username, self.password)
+        return r
+
+
+class HTTPProxyAuth(HTTPBasicAuth):
+    """Attaches HTTP Proxy Authentication to a given Request object."""
+
+    def __call__(self, r):
+        r.headers['Proxy-Authorization'] = _basic_auth_str(self.username, self.password)
+        return r
+
+
+class HTTPDigestAuth(AuthBase):
+    """Attaches HTTP Digest Authentication to the given Request object."""
+
+    def __init__(self, username, password):
+        self.username = username
+        self.password = password
+        # Keep state in per-thread local storage
+        self._thread_local = threading.local()
+
+    def init_per_thread_state(self):
+        # Ensure state is initialized just once per-thread
+        if not hasattr(self._thread_local, 'init'):
+            self._thread_local.init = True
+            self._thread_local.last_nonce = ''
+            self._thread_local.nonce_count = 0
+            self._thread_local.chal = {}
+            self._thread_local.pos = None
+            self._thread_local.num_401_calls = None
+
+    def build_digest_header(self, method, url):
+        """
+        :rtype: str
+        """
+
+        realm = self._thread_local.chal['realm']
+        nonce = self._thread_local.chal['nonce']
+        qop = self._thread_local.chal.get('qop')
+        algorithm = self._thread_local.chal.get('algorithm')
+        opaque = self._thread_local.chal.get('opaque')
+        hash_utf8 = None
+
+        if algorithm is None:
+            _algorithm = 'MD5'
+        else:
+            _algorithm = algorithm.upper()
+        # lambdas assume digest modules are imported at the top level
+        if _algorithm == 'MD5' or _algorithm == 'MD5-SESS':
+            def md5_utf8(x):
+                if isinstance(x, str):
+                    x = x.encode('utf-8')
+                return hashlib.md5(x).hexdigest()
+            hash_utf8 = md5_utf8
+        elif _algorithm == 'SHA':
+            def sha_utf8(x):
+                if isinstance(x, str):
+                    x = x.encode('utf-8')
+                return hashlib.sha1(x).hexdigest()
+            hash_utf8 = sha_utf8
+        elif _algorithm == 'SHA-256':
+            def sha256_utf8(x):
+                if isinstance(x, str):
+                    x = x.encode('utf-8')
+                return hashlib.sha256(x).hexdigest()
+            hash_utf8 = sha256_utf8
+        elif _algorithm == 'SHA-512':
+            def sha512_utf8(x):
+                if isinstance(x, str):
+                    x = x.encode('utf-8')
+                return hashlib.sha512(x).hexdigest()
+            hash_utf8 = sha512_utf8
+
+        KD = lambda s, d: hash_utf8("%s:%s" % (s, d))
+
+        if hash_utf8 is None:
+            return None
+
+        # XXX not implemented yet
+        entdig = None
+        p_parsed = urlparse(url)
+        #: path is request-uri defined in RFC 2616 which should not be empty
+        path = p_parsed.path or "/"
+        if p_parsed.query:
+            path += '?' + p_parsed.query
+
+        A1 = '%s:%s:%s' % (self.username, realm, self.password)
+        A2 = '%s:%s' % (method, path)
+
+        HA1 = hash_utf8(A1)
+        HA2 = hash_utf8(A2)
+
+        if nonce == self._thread_local.last_nonce:
+            self._thread_local.nonce_count += 1
+        else:
+            self._thread_local.nonce_count = 1
+        ncvalue = '%08x' % self._thread_local.nonce_count
+        s = str(self._thread_local.nonce_count).encode('utf-8')
+        s += nonce.encode('utf-8')
+        s += time.ctime().encode('utf-8')
+        s += os.urandom(8)
+
+        cnonce = (hashlib.sha1(s).hexdigest()[:16])
+        if _algorithm == 'MD5-SESS':
+            HA1 = hash_utf8('%s:%s:%s' % (HA1, nonce, cnonce))
+
+        if not qop:
+            respdig = KD(HA1, "%s:%s" % (nonce, HA2))
+        elif qop == 'auth' or 'auth' in qop.split(','):
+            noncebit = "%s:%s:%s:%s:%s" % (
+                nonce, ncvalue, cnonce, 'auth', HA2
+            )
+            respdig = KD(HA1, noncebit)
+        else:
+            # XXX handle auth-int.
+            return None
+
+        self._thread_local.last_nonce = nonce
+
+        # XXX should the partial digests be encoded too?
+        base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \
+               'response="%s"' % (self.username, realm, nonce, path, respdig)
+        if opaque:
+            base += ', opaque="%s"' % opaque
+        if algorithm:
+            base += ', algorithm="%s"' % algorithm
+        if entdig:
+            base += ', digest="%s"' % entdig
+        if qop:
+            base += ', qop="auth", nc=%s, cnonce="%s"' % (ncvalue, cnonce)
+
+        return 'Digest %s' % (base)
+
+    def handle_redirect(self, r, **kwargs):
+        """Reset num_401_calls counter on redirects."""
+        if r.is_redirect:
+            self._thread_local.num_401_calls = 1
+
+    def handle_401(self, r, **kwargs):
+        """
+        Takes the given response and tries digest-auth, if needed.
+
+        :rtype: requests.Response
+        """
+
+        # If response is not 4xx, do not auth
+        # See https://github.com/psf/requests/issues/3772
+        if not 400 <= r.status_code < 500:
+            self._thread_local.num_401_calls = 1
+            return r
+
+        if self._thread_local.pos is not None:
+            # Rewind the file position indicator of the body to where
+            # it was to resend the request.
+            r.request.body.seek(self._thread_local.pos)
+        s_auth = r.headers.get('www-authenticate', '')
+
+        if 'digest' in s_auth.lower() and self._thread_local.num_401_calls < 2:
+
+            self._thread_local.num_401_calls += 1
+            pat = re.compile(r'digest ', flags=re.IGNORECASE)
+            self._thread_local.chal = parse_dict_header(pat.sub('', s_auth, count=1))
+
+            # Consume content and release the original connection
+            # to allow our new request to reuse the same one.
+            r.content
+            r.close()
+            prep = r.request.copy()
+            extract_cookies_to_jar(prep._cookies, r.request, r.raw)
+            prep.prepare_cookies(prep._cookies)
+
+            prep.headers['Authorization'] = self.build_digest_header(
+                prep.method, prep.url)
+            _r = r.connection.send(prep, **kwargs)
+            _r.history.append(r)
+            _r.request = prep
+
+            return _r
+
+        self._thread_local.num_401_calls = 1
+        return r
+
+    def __call__(self, r):
+        # Initialize per-thread state, if needed
+        self.init_per_thread_state()
+        # If we have a saved nonce, skip the 401
+        if self._thread_local.last_nonce:
+            r.headers['Authorization'] = self.build_digest_header(r.method, r.url)
+        try:
+            self._thread_local.pos = r.body.tell()
+        except AttributeError:
+            # In the case of HTTPDigestAuth being reused and the body of
+            # the previous request was a file-like object, pos has the
+            # file position of the previous body. Ensure it's set to
+            # None.
+            self._thread_local.pos = None
+        r.register_hook('response', self.handle_401)
+        r.register_hook('response', self.handle_redirect)
+        self._thread_local.num_401_calls = 1
+
+        return r
+
+    def __eq__(self, other):
+        return all([
+            self.username == getattr(other, 'username', None),
+            self.password == getattr(other, 'password', None)
+        ])
+
+    def __ne__(self, other):
+        return not self == other

venv/Lib/site-packages/pip/_vendor/requests/certs.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+requests.certs
+~~~~~~~~~~~~~~
+
+This module returns the preferred default CA certificate bundle. There is
+only one — the one from the certifi package.
+
+If you are packaging Requests, e.g., for a Linux distribution or a managed
+environment, you can change the definition of where() to return a separately
+packaged CA bundle.
+"""
+from pip._vendor.certifi import where
+
+if __name__ == '__main__':
+    print(where())

venv/Lib/site-packages/pip/_vendor/requests/compat.py

@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.compat
+~~~~~~~~~~~~~~~
+
+This module handles import compatibility issues between Python 2 and
+Python 3.
+"""
+
+from pip._vendor import chardet
+
+import sys
+
+# -------
+# Pythons
+# -------
+
+# Syntax sugar.
+_ver = sys.version_info
+
+#: Python 2.x?
+is_py2 = (_ver[0] == 2)
+
+#: Python 3.x?
+is_py3 = (_ver[0] == 3)
+
+# Note: We've patched out simplejson support in pip because it prevents
+#       upgrading simplejson on Windows.
+# try:
+#     import simplejson as json
+# except (ImportError, SyntaxError):
+#     # simplejson does not support Python 3.2, it throws a SyntaxError
+#     # because of u'...' Unicode literals.
+import json
+
+# ---------
+# Specifics
+# ---------
+
+if is_py2:
+    from urllib import (
+        quote, unquote, quote_plus, unquote_plus, urlencode, getproxies,
+        proxy_bypass, proxy_bypass_environment, getproxies_environment)
+    from urlparse import urlparse, urlunparse, urljoin, urlsplit, urldefrag
+    from urllib2 import parse_http_list
+    import cookielib
+    from Cookie import Morsel
+    from StringIO import StringIO
+    # Keep OrderedDict for backwards compatibility.
+    from collections import Callable, Mapping, MutableMapping, OrderedDict
+
+
+    builtin_str = str
+    bytes = str
+    str = unicode
+    basestring = basestring
+    numeric_types = (int, long, float)
+    integer_types = (int, long)
+
+elif is_py3:
+    from urllib.parse import urlparse, urlunparse, urljoin, urlsplit, urlencode, quote, unquote, quote_plus, unquote_plus, urldefrag
+    from urllib.request import parse_http_list, getproxies, proxy_bypass, proxy_bypass_environment, getproxies_environment
+    from http import cookiejar as cookielib
+    from http.cookies import Morsel
+    from io import StringIO
+    # Keep OrderedDict for backwards compatibility.
+    from collections import OrderedDict
+    from collections.abc import Callable, Mapping, MutableMapping
+
+    builtin_str = str
+    str = str
+    bytes = bytes
+    basestring = (str, bytes)
+    numeric_types = (int, float)
+    integer_types = (int,)

venv/Lib/site-packages/pip/_vendor/requests/cookies.py

@@ -0,0 +1,549 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.cookies
+~~~~~~~~~~~~~~~~
+
+Compatibility code to be able to use `cookielib.CookieJar` with requests.
+
+requests.utils imports from here, so be careful with imports.
+"""
+
+import copy
+import time
+import calendar
+
+from ._internal_utils import to_native_string
+from .compat import cookielib, urlparse, urlunparse, Morsel, MutableMapping
+
+try:
+    import threading
+except ImportError:
+    import dummy_threading as threading
+
+
+class MockRequest(object):
+    """Wraps a `requests.Request` to mimic a `urllib2.Request`.
+
+    The code in `cookielib.CookieJar` expects this interface in order to correctly
+    manage cookie policies, i.e., determine whether a cookie can be set, given the
+    domains of the request and the cookie.
+
+    The original request object is read-only. The client is responsible for collecting
+    the new headers via `get_new_headers()` and interpreting them appropriately. You
+    probably want `get_cookie_header`, defined below.
+    """
+
+    def __init__(self, request):
+        self._r = request
+        self._new_headers = {}
+        self.type = urlparse(self._r.url).scheme
+
+    def get_type(self):
+        return self.type
+
+    def get_host(self):
+        return urlparse(self._r.url).netloc
+
+    def get_origin_req_host(self):
+        return self.get_host()
+
+    def get_full_url(self):
+        # Only return the response's URL if the user hadn't set the Host
+        # header
+        if not self._r.headers.get('Host'):
+            return self._r.url
+        # If they did set it, retrieve it and reconstruct the expected domain
+        host = to_native_string(self._r.headers['Host'], encoding='utf-8')
+        parsed = urlparse(self._r.url)
+        # Reconstruct the URL as we expect it
+        return urlunparse([
+            parsed.scheme, host, parsed.path, parsed.params, parsed.query,
+            parsed.fragment
+        ])
+
+    def is_unverifiable(self):
+        return True
+
+    def has_header(self, name):
+        return name in self._r.headers or name in self._new_headers
+
+    def get_header(self, name, default=None):
+        return self._r.headers.get(name, self._new_headers.get(name, default))
+
+    def add_header(self, key, val):
+        """cookielib has no legitimate use for this method; add it back if you find one."""
+        raise NotImplementedError("Cookie headers should be added with add_unredirected_header()")
+
+    def add_unredirected_header(self, name, value):
+        self._new_headers[name] = value
+
+    def get_new_headers(self):
+        return self._new_headers
+
+    @property
+    def unverifiable(self):
+        return self.is_unverifiable()
+
+    @property
+    def origin_req_host(self):
+        return self.get_origin_req_host()
+
+    @property
+    def host(self):
+        return self.get_host()
+
+
+class MockResponse(object):
+    """Wraps a `httplib.HTTPMessage` to mimic a `urllib.addinfourl`.
+
+    ...what? Basically, expose the parsed HTTP headers from the server response
+    the way `cookielib` expects to see them.
+    """
+
+    def __init__(self, headers):
+        """Make a MockResponse for `cookielib` to read.
+
+        :param headers: a httplib.HTTPMessage or analogous carrying the headers
+        """
+        self._headers = headers
+
+    def info(self):
+        return self._headers
+
+    def getheaders(self, name):
+        self._headers.getheaders(name)
+
+
+def extract_cookies_to_jar(jar, request, response):
+    """Extract the cookies from the response into a CookieJar.
+
+    :param jar: cookielib.CookieJar (not necessarily a RequestsCookieJar)
+    :param request: our own requests.Request object
+    :param response: urllib3.HTTPResponse object
+    """
+    if not (hasattr(response, '_original_response') and
+            response._original_response):
+        return
+    # the _original_response field is the wrapped httplib.HTTPResponse object,
+    req = MockRequest(request)
+    # pull out the HTTPMessage with the headers and put it in the mock:
+    res = MockResponse(response._original_response.msg)
+    jar.extract_cookies(res, req)
+
+
+def get_cookie_header(jar, request):
+    """
+    Produce an appropriate Cookie header string to be sent with `request`, or None.
+
+    :rtype: str
+    """
+    r = MockRequest(request)
+    jar.add_cookie_header(r)
+    return r.get_new_headers().get('Cookie')
+
+
+def remove_cookie_by_name(cookiejar, name, domain=None, path=None):
+    """Unsets a cookie by name, by default over all domains and paths.
+
+    Wraps CookieJar.clear(), is O(n).
+    """
+    clearables = []
+    for cookie in cookiejar:
+        if cookie.name != name:
+            continue
+        if domain is not None and domain != cookie.domain:
+            continue
+        if path is not None and path != cookie.path:
+            continue
+        clearables.append((cookie.domain, cookie.path, cookie.name))
+
+    for domain, path, name in clearables:
+        cookiejar.clear(domain, path, name)
+
+
+class CookieConflictError(RuntimeError):
+    """There are two cookies that meet the criteria specified in the cookie jar.
+    Use .get and .set and include domain and path args in order to be more specific.
+    """
+
+
+class RequestsCookieJar(cookielib.CookieJar, MutableMapping):
+    """Compatibility class; is a cookielib.CookieJar, but exposes a dict
+    interface.
+
+    This is the CookieJar we create by default for requests and sessions that
+    don't specify one, since some clients may expect response.cookies and
+    session.cookies to support dict operations.
+
+    Requests does not use the dict interface internally; it's just for
+    compatibility with external client code. All requests code should work
+    out of the box with externally provided instances of ``CookieJar``, e.g.
+    ``LWPCookieJar`` and ``FileCookieJar``.
+
+    Unlike a regular CookieJar, this class is pickleable.
+
+    .. warning:: dictionary operations that are normally O(1) may be O(n).
+    """
+
+    def get(self, name, default=None, domain=None, path=None):
+        """Dict-like get() that also supports optional domain and path args in
+        order to resolve naming collisions from using one cookie jar over
+        multiple domains.
+
+        .. warning:: operation is O(n), not O(1).
+        """
+        try:
+            return self._find_no_duplicates(name, domain, path)
+        except KeyError:
+            return default
+
+    def set(self, name, value, **kwargs):
+        """Dict-like set() that also supports optional domain and path args in
+        order to resolve naming collisions from using one cookie jar over
+        multiple domains.
+        """
+        # support client code that unsets cookies by assignment of a None value:
+        if value is None:
+            remove_cookie_by_name(self, name, domain=kwargs.get('domain'), path=kwargs.get('path'))
+            return
+
+        if isinstance(value, Morsel):
+            c = morsel_to_cookie(value)
+        else:
+            c = create_cookie(name, value, **kwargs)
+        self.set_cookie(c)
+        return c
+
+    def iterkeys(self):
+        """Dict-like iterkeys() that returns an iterator of names of cookies
+        from the jar.
+
+        .. seealso:: itervalues() and iteritems().
+        """
+        for cookie in iter(self):
+            yield cookie.name
+
+    def keys(self):
+        """Dict-like keys() that returns a list of names of cookies from the
+        jar.
+
+        .. seealso:: values() and items().
+        """
+        return list(self.iterkeys())
+
+    def itervalues(self):
+        """Dict-like itervalues() that returns an iterator of values of cookies
+        from the jar.
+
+        .. seealso:: iterkeys() and iteritems().
+        """
+        for cookie in iter(self):
+            yield cookie.value
+
+    def values(self):
+        """Dict-like values() that returns a list of values of cookies from the
+        jar.
+
+        .. seealso:: keys() and items().
+        """
+        return list(self.itervalues())
+
+    def iteritems(self):
+        """Dict-like iteritems() that returns an iterator of name-value tuples
+        from the jar.
+
+        .. seealso:: iterkeys() and itervalues().
+        """
+        for cookie in iter(self):
+            yield cookie.name, cookie.value
+
+    def items(self):
+        """Dict-like items() that returns a list of name-value tuples from the
+        jar. Allows client-code to call ``dict(RequestsCookieJar)`` and get a
+        vanilla python dict of key value pairs.
+
+        .. seealso:: keys() and values().
+        """
+        return list(self.iteritems())
+
+    def list_domains(self):
+        """Utility method to list all the domains in the jar."""
+        domains = []
+        for cookie in iter(self):
+            if cookie.domain not in domains:
+                domains.append(cookie.domain)
+        return domains
+
+    def list_paths(self):
+        """Utility method to list all the paths in the jar."""
+        paths = []
+        for cookie in iter(self):
+            if cookie.path not in paths:
+                paths.append(cookie.path)
+        return paths
+
+    def multiple_domains(self):
+        """Returns True if there are multiple domains in the jar.
+        Returns False otherwise.
+
+        :rtype: bool
+        """
+        domains = []
+        for cookie in iter(self):
+            if cookie.domain is not None and cookie.domain in domains:
+                return True
+            domains.append(cookie.domain)
+        return False  # there is only one domain in jar
+
+    def get_dict(self, domain=None, path=None):
+        """Takes as an argument an optional domain and path and returns a plain
+        old Python dict of name-value pairs of cookies that meet the
+        requirements.
+
+        :rtype: dict
+        """
+        dictionary = {}
+        for cookie in iter(self):
+            if (
+                (domain is None or cookie.domain == domain) and
+                (path is None or cookie.path == path)
+            ):
+                dictionary[cookie.name] = cookie.value
+        return dictionary
+
+    def __contains__(self, name):
+        try:
+            return super(RequestsCookieJar, self).__contains__(name)
+        except CookieConflictError:
+            return True
+
+    def __getitem__(self, name):
+        """Dict-like __getitem__() for compatibility with client code. Throws
+        exception if there are more than one cookie with name. In that case,
+        use the more explicit get() method instead.
+
+        .. warning:: operation is O(n), not O(1).
+        """
+        return self._find_no_duplicates(name)
+
+    def __setitem__(self, name, value):
+        """Dict-like __setitem__ for compatibility with client code. Throws
+        exception if there is already a cookie of that name in the jar. In that
+        case, use the more explicit set() method instead.
+        """
+        self.set(name, value)
+
+    def __delitem__(self, name):
+        """Deletes a cookie given a name. Wraps ``cookielib.CookieJar``'s
+        ``remove_cookie_by_name()``.
+        """
+        remove_cookie_by_name(self, name)
+
+    def set_cookie(self, cookie, *args, **kwargs):
+        if hasattr(cookie.value, 'startswith') and cookie.value.startswith('"') and cookie.value.endswith('"'):
+            cookie.value = cookie.value.replace('\\"', '')
+        return super(RequestsCookieJar, self).set_cookie(cookie, *args, **kwargs)
+
+    def update(self, other):
+        """Updates this jar with cookies from another CookieJar or dict-like"""
+        if isinstance(other, cookielib.CookieJar):
+            for cookie in other:
+                self.set_cookie(copy.copy(cookie))
+        else:
+            super(RequestsCookieJar, self).update(other)
+
+    def _find(self, name, domain=None, path=None):
+        """Requests uses this method internally to get cookie values.
+
+        If there are conflicting cookies, _find arbitrarily chooses one.
+        See _find_no_duplicates if you want an exception thrown if there are
+        conflicting cookies.
+
+        :param name: a string containing name of cookie
+        :param domain: (optional) string containing domain of cookie
+        :param path: (optional) string containing path of cookie
+        :return: cookie.value
+        """
+        for cookie in iter(self):
+            if cookie.name == name:
+                if domain is None or cookie.domain == domain:
+                    if path is None or cookie.path == path:
+                        return cookie.value
+
+        raise KeyError('name=%r, domain=%r, path=%r' % (name, domain, path))
+
+    def _find_no_duplicates(self, name, domain=None, path=None):
+        """Both ``__get_item__`` and ``get`` call this function: it's never
+        used elsewhere in Requests.
+
+        :param name: a string containing name of cookie
+        :param domain: (optional) string containing domain of cookie
+        :param path: (optional) string containing path of cookie
+        :raises KeyError: if cookie is not found
+        :raises CookieConflictError: if there are multiple cookies
+            that match name and optionally domain and path
+        :return: cookie.value
+        """
+        toReturn = None
+        for cookie in iter(self):
+            if cookie.name == name:
+                if domain is None or cookie.domain == domain:
+                    if path is None or cookie.path == path:
+                        if toReturn is not None:  # if there are multiple cookies that meet passed in criteria
+                            raise CookieConflictError('There are multiple cookies with name, %r' % (name))
+                        toReturn = cookie.value  # we will eventually return this as long as no cookie conflict
+
+        if toReturn:
+            return toReturn
+        raise KeyError('name=%r, domain=%r, path=%r' % (name, domain, path))
+
+    def __getstate__(self):
+        """Unlike a normal CookieJar, this class is pickleable."""
+        state = self.__dict__.copy()
+        # remove the unpickleable RLock object
+        state.pop('_cookies_lock')
+        return state
+
+    def __setstate__(self, state):
+        """Unlike a normal CookieJar, this class is pickleable."""
+        self.__dict__.update(state)
+        if '_cookies_lock' not in self.__dict__:
+            self._cookies_lock = threading.RLock()
+
+    def copy(self):
+        """Return a copy of this RequestsCookieJar."""
+        new_cj = RequestsCookieJar()
+        new_cj.set_policy(self.get_policy())
+        new_cj.update(self)
+        return new_cj
+
+    def get_policy(self):
+        """Return the CookiePolicy instance used."""
+        return self._policy
+
+
+def _copy_cookie_jar(jar):
+    if jar is None:
+        return None
+
+    if hasattr(jar, 'copy'):
+        # We're dealing with an instance of RequestsCookieJar
+        return jar.copy()
+    # We're dealing with a generic CookieJar instance
+    new_jar = copy.copy(jar)
+    new_jar.clear()
+    for cookie in jar:
+        new_jar.set_cookie(copy.copy(cookie))
+    return new_jar
+
+
+def create_cookie(name, value, **kwargs):
+    """Make a cookie from underspecified parameters.
+
+    By default, the pair of `name` and `value` will be set for the domain ''
+    and sent on every request (this is sometimes called a "supercookie").
+    """
+    result = {
+        'version': 0,
+        'name': name,
+        'value': value,
+        'port': None,
+        'domain': '',
+        'path': '/',
+        'secure': False,
+        'expires': None,
+        'discard': True,
+        'comment': None,
+        'comment_url': None,
+        'rest': {'HttpOnly': None},
+        'rfc2109': False,
+    }
+
+    badargs = set(kwargs) - set(result)
+    if badargs:
+        err = 'create_cookie() got unexpected keyword arguments: %s'
+        raise TypeError(err % list(badargs))
+
+    result.update(kwargs)
+    result['port_specified'] = bool(result['port'])
+    result['domain_specified'] = bool(result['domain'])
+    result['domain_initial_dot'] = result['domain'].startswith('.')
+    result['path_specified'] = bool(result['path'])
+
+    return cookielib.Cookie(**result)
+
+
+def morsel_to_cookie(morsel):
+    """Convert a Morsel object into a Cookie containing the one k/v pair."""
+
+    expires = None
+    if morsel['max-age']:
+        try:
+            expires = int(time.time() + int(morsel['max-age']))
+        except ValueError:
+            raise TypeError('max-age: %s must be integer' % morsel['max-age'])
+    elif morsel['expires']:
+        time_template = '%a, %d-%b-%Y %H:%M:%S GMT'
+        expires = calendar.timegm(
+            time.strptime(morsel['expires'], time_template)
+        )
+    return create_cookie(
+        comment=morsel['comment'],
+        comment_url=bool(morsel['comment']),
+        discard=False,
+        domain=morsel['domain'],
+        expires=expires,
+        name=morsel.key,
+        path=morsel['path'],
+        port=None,
+        rest={'HttpOnly': morsel['httponly']},
+        rfc2109=False,
+        secure=bool(morsel['secure']),
+        value=morsel.value,
+        version=morsel['version'] or 0,
+    )
+
+
+def cookiejar_from_dict(cookie_dict, cookiejar=None, overwrite=True):
+    """Returns a CookieJar from a key/value dictionary.
+
+    :param cookie_dict: Dict of key/values to insert into CookieJar.
+    :param cookiejar: (optional) A cookiejar to add the cookies to.
+    :param overwrite: (optional) If False, will not replace cookies
+        already in the jar with new ones.
+    :rtype: CookieJar
+    """
+    if cookiejar is None:
+        cookiejar = RequestsCookieJar()
+
+    if cookie_dict is not None:
+        names_from_jar = [cookie.name for cookie in cookiejar]
+        for name in cookie_dict:
+            if overwrite or (name not in names_from_jar):
+                cookiejar.set_cookie(create_cookie(name, cookie_dict[name]))
+
+    return cookiejar
+
+
+def merge_cookies(cookiejar, cookies):
+    """Add cookies to cookiejar and returns a merged CookieJar.
+
+    :param cookiejar: CookieJar object to add the cookies to.
+    :param cookies: Dictionary or CookieJar object to be added.
+    :rtype: CookieJar
+    """
+    if not isinstance(cookiejar, cookielib.CookieJar):
+        raise ValueError('You can only merge into CookieJar')
+
+    if isinstance(cookies, dict):
+        cookiejar = cookiejar_from_dict(
+            cookies, cookiejar=cookiejar, overwrite=False)
+    elif isinstance(cookies, cookielib.CookieJar):
+        try:
+            cookiejar.update(cookies)
+        except AttributeError:
+            for cookie_in_jar in cookies:
+                cookiejar.set_cookie(cookie_in_jar)
+
+    return cookiejar

venv/Lib/site-packages/pip/_vendor/requests/exceptions.py

@@ -0,0 +1,123 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.exceptions
+~~~~~~~~~~~~~~~~~~~
+
+This module contains the set of Requests' exceptions.
+"""
+from pip._vendor.urllib3.exceptions import HTTPError as BaseHTTPError
+
+
+class RequestException(IOError):
+    """There was an ambiguous exception that occurred while handling your
+    request.
+    """
+
+    def __init__(self, *args, **kwargs):
+        """Initialize RequestException with `request` and `response` objects."""
+        response = kwargs.pop('response', None)
+        self.response = response
+        self.request = kwargs.pop('request', None)
+        if (response is not None and not self.request and
+                hasattr(response, 'request')):
+            self.request = self.response.request
+        super(RequestException, self).__init__(*args, **kwargs)
+
+
+class HTTPError(RequestException):
+    """An HTTP error occurred."""
+
+
+class ConnectionError(RequestException):
+    """A Connection error occurred."""
+
+
+class ProxyError(ConnectionError):
+    """A proxy error occurred."""
+
+
+class SSLError(ConnectionError):
+    """An SSL error occurred."""
+
+
+class Timeout(RequestException):
+    """The request timed out.
+
+    Catching this error will catch both
+    :exc:`~requests.exceptions.ConnectTimeout` and
+    :exc:`~requests.exceptions.ReadTimeout` errors.
+    """
+
+
+class ConnectTimeout(ConnectionError, Timeout):
+    """The request timed out while trying to connect to the remote server.
+
+    Requests that produced this error are safe to retry.
+    """
+
+
+class ReadTimeout(Timeout):
+    """The server did not send any data in the allotted amount of time."""
+
+
+class URLRequired(RequestException):
+    """A valid URL is required to make a request."""
+
+
+class TooManyRedirects(RequestException):
+    """Too many redirects."""
+
+
+class MissingSchema(RequestException, ValueError):
+    """The URL schema (e.g. http or https) is missing."""
+
+
+class InvalidSchema(RequestException, ValueError):
+    """See defaults.py for valid schemas."""
+
+
+class InvalidURL(RequestException, ValueError):
+    """The URL provided was somehow invalid."""
+
+
+class InvalidHeader(RequestException, ValueError):
+    """The header value provided was somehow invalid."""
+
+
+class InvalidProxyURL(InvalidURL):
+    """The proxy URL provided is invalid."""
+
+
+class ChunkedEncodingError(RequestException):
+    """The server declared chunked encoding but sent an invalid chunk."""
+
+
+class ContentDecodingError(RequestException, BaseHTTPError):
+    """Failed to decode response content."""
+
+
+class StreamConsumedError(RequestException, TypeError):
+    """The content for this response was already consumed."""
+
+
+class RetryError(RequestException):
+    """Custom retries logic failed"""
+
+
+class UnrewindableBodyError(RequestException):
+    """Requests encountered an error when trying to rewind a body."""
+
+# Warnings
+
+
+class RequestsWarning(Warning):
+    """Base warning for Requests."""
+
+
+class FileModeWarning(RequestsWarning, DeprecationWarning):
+    """A file was opened in text mode, but Requests determined its binary length."""
+
+
+class RequestsDependencyWarning(RequestsWarning):
+    """An imported dependency doesn't match the expected version range."""

venv/Lib/site-packages/pip/_vendor/requests/help.py

@@ -0,0 +1,119 @@
+"""Module containing bug report helper(s)."""
+from __future__ import print_function
+
+import json
+import platform
+import sys
+import ssl
+
+from pip._vendor import idna
+from pip._vendor import urllib3
+from pip._vendor import chardet
+
+from . import __version__ as requests_version
+
+try:
+    from pip._vendor.urllib3.contrib import pyopenssl
+except ImportError:
+    pyopenssl = None
+    OpenSSL = None
+    cryptography = None
+else:
+    import OpenSSL
+    import cryptography
+
+
+def _implementation():
+    """Return a dict with the Python implementation and version.
+
+    Provide both the name and the version of the Python implementation
+    currently running. For example, on CPython 2.7.5 it will return
+    {'name': 'CPython', 'version': '2.7.5'}.
+
+    This function works best on CPython and PyPy: in particular, it probably
+    doesn't work for Jython or IronPython. Future investigation should be done
+    to work out the correct shape of the code for those platforms.
+    """
+    implementation = platform.python_implementation()
+
+    if implementation == 'CPython':
+        implementation_version = platform.python_version()
+    elif implementation == 'PyPy':
+        implementation_version = '%s.%s.%s' % (sys.pypy_version_info.major,
+                                               sys.pypy_version_info.minor,
+                                               sys.pypy_version_info.micro)
+        if sys.pypy_version_info.releaselevel != 'final':
+            implementation_version = ''.join([
+                implementation_version, sys.pypy_version_info.releaselevel
+            ])
+    elif implementation == 'Jython':
+        implementation_version = platform.python_version()  # Complete Guess
+    elif implementation == 'IronPython':
+        implementation_version = platform.python_version()  # Complete Guess
+    else:
+        implementation_version = 'Unknown'
+
+    return {'name': implementation, 'version': implementation_version}
+
+
+def info():
+    """Generate information for a bug report."""
+    try:
+        platform_info = {
+            'system': platform.system(),
+            'release': platform.release(),
+        }
+    except IOError:
+        platform_info = {
+            'system': 'Unknown',
+            'release': 'Unknown',
+        }
+
+    implementation_info = _implementation()
+    urllib3_info = {'version': urllib3.__version__}
+    chardet_info = {'version': chardet.__version__}
+
+    pyopenssl_info = {
+        'version': None,
+        'openssl_version': '',
+    }
+    if OpenSSL:
+        pyopenssl_info = {
+            'version': OpenSSL.__version__,
+            'openssl_version': '%x' % OpenSSL.SSL.OPENSSL_VERSION_NUMBER,
+        }
+    cryptography_info = {
+        'version': getattr(cryptography, '__version__', ''),
+    }
+    idna_info = {
+        'version': getattr(idna, '__version__', ''),
+    }
+
+    system_ssl = ssl.OPENSSL_VERSION_NUMBER
+    system_ssl_info = {
+        'version': '%x' % system_ssl if system_ssl is not None else ''
+    }
+
+    return {
+        'platform': platform_info,
+        'implementation': implementation_info,
+        'system_ssl': system_ssl_info,
+        'using_pyopenssl': pyopenssl is not None,
+        'pyOpenSSL': pyopenssl_info,
+        'urllib3': urllib3_info,
+        'chardet': chardet_info,
+        'cryptography': cryptography_info,
+        'idna': idna_info,
+        'requests': {
+            'version': requests_version,
+        },
+    }
+
+
+def main():
+    """Pretty-print the bug information as JSON."""
+    print(json.dumps(info(), sort_keys=True, indent=2))
+
+
+if __name__ == '__main__':
+    main()

venv/Lib/site-packages/pip/_vendor/requests/hooks.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.hooks
+~~~~~~~~~~~~~~
+
+This module provides the capabilities for the Requests hooks system.
+
+Available hooks:
+
+``response``:
+    The response generated from a Request.
+"""
+HOOKS = ['response']
+
+
+def default_hooks():
+    return {event: [] for event in HOOKS}
+
+# TODO: response is the only one
+
+
+def dispatch_hook(key, hooks, hook_data, **kwargs):
+    """Dispatches a hook dictionary on a given piece of data."""
+    hooks = hooks or {}
+    hooks = hooks.get(key)
+    if hooks:
+        if hasattr(hooks, '__call__'):
+            hooks = [hooks]
+        for hook in hooks:
+            _hook_data = hook(hook_data, **kwargs)
+            if _hook_data is not None:
+                hook_data = _hook_data
+    return hook_data

venv/Lib/site-packages/pip/_vendor/requests/models.py

@@ -0,0 +1,954 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.models
+~~~~~~~~~~~~~~~
+
+This module contains the primary objects that power Requests.
+"""
+
+import datetime
+import sys
+
+# Import encoding now, to avoid implicit import later.
+# Implicit import within threads may cause LookupError when standard library is in a ZIP,
+# such as in Embedded Python. See https://github.com/psf/requests/issues/3578.
+import encodings.idna
+
+from pip._vendor.urllib3.fields import RequestField
+from pip._vendor.urllib3.filepost import encode_multipart_formdata
+from pip._vendor.urllib3.util import parse_url
+from pip._vendor.urllib3.exceptions import (
+    DecodeError, ReadTimeoutError, ProtocolError, LocationParseError)
+
+from io import UnsupportedOperation
+from .hooks import default_hooks
+from .structures import CaseInsensitiveDict
+
+from .auth import HTTPBasicAuth
+from .cookies import cookiejar_from_dict, get_cookie_header, _copy_cookie_jar
+from .exceptions import (
+    HTTPError, MissingSchema, InvalidURL, ChunkedEncodingError,
+    ContentDecodingError, ConnectionError, StreamConsumedError)
+from ._internal_utils import to_native_string, unicode_is_ascii
+from .utils import (
+    guess_filename, get_auth_from_url, requote_uri,
+    stream_decode_response_unicode, to_key_val_list, parse_header_links,
+    iter_slices, guess_json_utf, super_len, check_header_validity)
+from .compat import (
+    Callable, Mapping,
+    cookielib, urlunparse, urlsplit, urlencode, str, bytes,
+    is_py2, chardet, builtin_str, basestring)
+from .compat import json as complexjson
+from .status_codes import codes
+
+#: The set of HTTP status codes that indicate an automatically
+#: processable redirect.
+REDIRECT_STATI = (
+    codes.moved,               # 301
+    codes.found,               # 302
+    codes.other,               # 303
+    codes.temporary_redirect,  # 307
+    codes.permanent_redirect,  # 308
+)
+
+DEFAULT_REDIRECT_LIMIT = 30
+CONTENT_CHUNK_SIZE = 10 * 1024
+ITER_CHUNK_SIZE = 512
+
+
+class RequestEncodingMixin(object):
+    @property
+    def path_url(self):
+        """Build the path URL to use."""
+
+        url = []
+
+        p = urlsplit(self.url)
+
+        path = p.path
+        if not path:
+            path = '/'
+
+        url.append(path)
+
+        query = p.query
+        if query:
+            url.append('?')
+            url.append(query)
+
+        return ''.join(url)
+
+    @staticmethod
+    def _encode_params(data):
+        """Encode parameters in a piece of data.
+
+        Will successfully encode parameters when passed as a dict or a list of
+        2-tuples. Order is retained if data is a list of 2-tuples but arbitrary
+        if parameters are supplied as a dict.
+        """
+
+        if isinstance(data, (str, bytes)):
+            return data
+        elif hasattr(data, 'read'):
+            return data
+        elif hasattr(data, '__iter__'):
+            result = []
+            for k, vs in to_key_val_list(data):
+                if isinstance(vs, basestring) or not hasattr(vs, '__iter__'):
+                    vs = [vs]
+                for v in vs:
+                    if v is not None:
+                        result.append(
+                            (k.encode('utf-8') if isinstance(k, str) else k,
+                             v.encode('utf-8') if isinstance(v, str) else v))
+            return urlencode(result, doseq=True)
+        else:
+            return data
+
+    @staticmethod
+    def _encode_files(files, data):
+        """Build the body for a multipart/form-data request.
+
+        Will successfully encode files when passed as a dict or a list of
+        tuples. Order is retained if data is a list of tuples but arbitrary
+        if parameters are supplied as a dict.
+        The tuples may be 2-tuples (filename, fileobj), 3-tuples (filename, fileobj, contentype)
+        or 4-tuples (filename, fileobj, contentype, custom_headers).
+        """
+        if (not files):
+            raise ValueError("Files must be provided.")
+        elif isinstance(data, basestring):
+            raise ValueError("Data must not be a string.")
+
+        new_fields = []
+        fields = to_key_val_list(data or {})
+        files = to_key_val_list(files or {})
+
+        for field, val in fields:
+            if isinstance(val, basestring) or not hasattr(val, '__iter__'):
+                val = [val]
+            for v in val:
+                if v is not None:
+                    # Don't call str() on bytestrings: in Py3 it all goes wrong.
+                    if not isinstance(v, bytes):
+                        v = str(v)
+
+                    new_fields.append(
+                        (field.decode('utf-8') if isinstance(field, bytes) else field,
+                         v.encode('utf-8') if isinstance(v, str) else v))
+
+        for (k, v) in files:
+            # support for explicit filename
+            ft = None
+            fh = None
+            if isinstance(v, (tuple, list)):
+                if len(v) == 2:
+                    fn, fp = v
+                elif len(v) == 3:
+                    fn, fp, ft = v
+                else:
+                    fn, fp, ft, fh = v
+            else:
+                fn = guess_filename(v) or k
+                fp = v
+
+            if isinstance(fp, (str, bytes, bytearray)):
+                fdata = fp
+            elif hasattr(fp, 'read'):
+                fdata = fp.read()
+            elif fp is None:
+                continue
+            else:
+                fdata = fp
+
+            rf = RequestField(name=k, data=fdata, filename=fn, headers=fh)
+            rf.make_multipart(content_type=ft)
+            new_fields.append(rf)
+
+        body, content_type = encode_multipart_formdata(new_fields)
+
+        return body, content_type
+
+
+class RequestHooksMixin(object):
+    def register_hook(self, event, hook):
+        """Properly register a hook."""
+
+        if event not in self.hooks:
+            raise ValueError('Unsupported event specified, with event name "%s"' % (event))
+
+        if isinstance(hook, Callable):
+            self.hooks[event].append(hook)
+        elif hasattr(hook, '__iter__'):
+            self.hooks[event].extend(h for h in hook if isinstance(h, Callable))
+
+    def deregister_hook(self, event, hook):
+        """Deregister a previously registered hook.
+        Returns True if the hook existed, False if not.
+        """
+
+        try:
+            self.hooks[event].remove(hook)
+            return True
+        except ValueError:
+            return False
+
+
+class Request(RequestHooksMixin):
+    """A user-created :class:`Request <Request>` object.
+
+    Used to prepare a :class:`PreparedRequest <PreparedRequest>`, which is sent to the server.
+
+    :param method: HTTP method to use.
+    :param url: URL to send.
+    :param headers: dictionary of headers to send.
+    :param files: dictionary of {filename: fileobject} files to multipart upload.
+    :param data: the body to attach to the request. If a dictionary or
+        list of tuples ``[(key, value)]`` is provided, form-encoding will
+        take place.
+    :param json: json for the body to attach to the request (if files or data is not specified).
+    :param params: URL parameters to append to the URL. If a dictionary or
+        list of tuples ``[(key, value)]`` is provided, form-encoding will
+        take place.
+    :param auth: Auth handler or (user, pass) tuple.
+    :param cookies: dictionary or CookieJar of cookies to attach to this request.
+    :param hooks: dictionary of callback hooks, for internal usage.
+
+    Usage::
+
+      >>> import requests
+      >>> req = requests.Request('GET', 'https://httpbin.org/get')
+      >>> req.prepare()
+      <PreparedRequest [GET]>
+    """
+
+    def __init__(self,
+            method=None, url=None, headers=None, files=None, data=None,
+            params=None, auth=None, cookies=None, hooks=None, json=None):
+
+        # Default empty dicts for dict params.
+        data = [] if data is None else data
+        files = [] if files is None else files
+        headers = {} if headers is None else headers
+        params = {} if params is None else params
+        hooks = {} if hooks is None else hooks
+
+        self.hooks = default_hooks()
+        for (k, v) in list(hooks.items()):
+            self.register_hook(event=k, hook=v)
+
+        self.method = method
+        self.url = url
+        self.headers = headers
+        self.files = files
+        self.data = data
+        self.json = json
+        self.params = params
+        self.auth = auth
+        self.cookies = cookies
+
+    def __repr__(self):
+        return '<Request [%s]>' % (self.method)
+
+    def prepare(self):
+        """Constructs a :class:`PreparedRequest <PreparedRequest>` for transmission and returns it."""
+        p = PreparedRequest()
+        p.prepare(
+            method=self.method,
+            url=self.url,
+            headers=self.headers,
+            files=self.files,
+            data=self.data,
+            json=self.json,
+            params=self.params,
+            auth=self.auth,
+            cookies=self.cookies,
+            hooks=self.hooks,
+        )
+        return p
+
+
+class PreparedRequest(RequestEncodingMixin, RequestHooksMixin):
+    """The fully mutable :class:`PreparedRequest <PreparedRequest>` object,
+    containing the exact bytes that will be sent to the server.
+
+    Generated from either a :class:`Request <Request>` object or manually.
+
+    Usage::
+
+      >>> import requests
+      >>> req = requests.Request('GET', 'https://httpbin.org/get')
+      >>> r = req.prepare()
+      >>> r
+      <PreparedRequest [GET]>
+
+      >>> s = requests.Session()
+      >>> s.send(r)
+      <Response [200]>
+    """
+
+    def __init__(self):
+        #: HTTP verb to send to the server.
+        self.method = None
+        #: HTTP URL to send the request to.
+        self.url = None
+        #: dictionary of HTTP headers.
+        self.headers = None
+        # The `CookieJar` used to create the Cookie header will be stored here
+        # after prepare_cookies is called
+        self._cookies = None
+        #: request body to send to the server.
+        self.body = None
+        #: dictionary of callback hooks, for internal usage.
+        self.hooks = default_hooks()
+        #: integer denoting starting position of a readable file-like body.
+        self._body_position = None
+
+    def prepare(self,
+            method=None, url=None, headers=None, files=None, data=None,
+            params=None, auth=None, cookies=None, hooks=None, json=None):
+        """Prepares the entire request with the given parameters."""
+
+        self.prepare_method(method)
+        self.prepare_url(url, params)
+        self.prepare_headers(headers)
+        self.prepare_cookies(cookies)
+        self.prepare_body(data, files, json)
+        self.prepare_auth(auth, url)
+
+        # Note that prepare_auth must be last to enable authentication schemes
+        # such as OAuth to work on a fully prepared request.
+
+        # This MUST go after prepare_auth. Authenticators could add a hook
+        self.prepare_hooks(hooks)
+
+    def __repr__(self):
+        return '<PreparedRequest [%s]>' % (self.method)
+
+    def copy(self):
+        p = PreparedRequest()
+        p.method = self.method
+        p.url = self.url
+        p.headers = self.headers.copy() if self.headers is not None else None
+        p._cookies = _copy_cookie_jar(self._cookies)
+        p.body = self.body
+        p.hooks = self.hooks
+        p._body_position = self._body_position
+        return p
+
+    def prepare_method(self, method):
+        """Prepares the given HTTP method."""
+        self.method = method
+        if self.method is not None:
+            self.method = to_native_string(self.method.upper())
+
+    @staticmethod
+    def _get_idna_encoded_host(host):
+        from pip._vendor import idna
+
+        try:
+            host = idna.encode(host, uts46=True).decode('utf-8')
+        except idna.IDNAError:
+            raise UnicodeError
+        return host
+
+    def prepare_url(self, url, params):
+        """Prepares the given HTTP URL."""
+        #: Accept objects that have string representations.
+        #: We're unable to blindly call unicode/str functions
+        #: as this will include the bytestring indicator (b'')
+        #: on python 3.x.
+        #: https://github.com/psf/requests/pull/2238
+        if isinstance(url, bytes):
+            url = url.decode('utf8')
+        else:
+            url = unicode(url) if is_py2 else str(url)
+
+        # Remove leading whitespaces from url
+        url = url.lstrip()
+
+        # Don't do any URL preparation for non-HTTP schemes like `mailto`,
+        # `data` etc to work around exceptions from `url_parse`, which
+        # handles RFC 3986 only.
+        if ':' in url and not url.lower().startswith('http'):
+            self.url = url
+            return
+
+        # Support for unicode domain names and paths.
+        try:
+            scheme, auth, host, port, path, query, fragment = parse_url(url)
+        except LocationParseError as e:
+            raise InvalidURL(*e.args)
+
+        if not scheme:
+            error = ("Invalid URL {0!r}: No schema supplied. Perhaps you meant http://{0}?")
+            error = error.format(to_native_string(url, 'utf8'))
+
+            raise MissingSchema(error)
+
+        if not host:
+            raise InvalidURL("Invalid URL %r: No host supplied" % url)
+
+        # In general, we want to try IDNA encoding the hostname if the string contains
+        # non-ASCII characters. This allows users to automatically get the correct IDNA
+        # behaviour. For strings containing only ASCII characters, we need to also verify
+        # it doesn't start with a wildcard (*), before allowing the unencoded hostname.
+        if not unicode_is_ascii(host):
+            try:
+                host = self._get_idna_encoded_host(host)
+            except UnicodeError:
+                raise InvalidURL('URL has an invalid label.')
+        elif host.startswith(u'*'):
+            raise InvalidURL('URL has an invalid label.')
+
+        # Carefully reconstruct the network location
+        netloc = auth or ''
+        if netloc:
+            netloc += '@'
+        netloc += host
+        if port:
+            netloc += ':' + str(port)
+
+        # Bare domains aren't valid URLs.
+        if not path:
+            path = '/'
+
+        if is_py2:
+            if isinstance(scheme, str):
+                scheme = scheme.encode('utf-8')
+            if isinstance(netloc, str):
+                netloc = netloc.encode('utf-8')
+            if isinstance(path, str):
+                path = path.encode('utf-8')
+            if isinstance(query, str):
+                query = query.encode('utf-8')
+            if isinstance(fragment, str):
+                fragment = fragment.encode('utf-8')
+
+        if isinstance(params, (str, bytes)):
+            params = to_native_string(params)
+
+        enc_params = self._encode_params(params)
+        if enc_params:
+            if query:
+                query = '%s&%s' % (query, enc_params)
+            else:
+                query = enc_params
+
+        url = requote_uri(urlunparse([scheme, netloc, path, None, query, fragment]))
+        self.url = url
+
+    def prepare_headers(self, headers):
+        """Prepares the given HTTP headers."""
+
+        self.headers = CaseInsensitiveDict()
+        if headers:
+            for header in headers.items():
+                # Raise exception on invalid header value.
+                check_header_validity(header)
+                name, value = header
+                self.headers[to_native_string(name)] = value
+
+    def prepare_body(self, data, files, json=None):
+        """Prepares the given HTTP body data."""
+
+        # Check if file, fo, generator, iterator.
+        # If not, run through normal process.
+
+        # Nottin' on you.
+        body = None
+        content_type = None
+
+        if not data and json is not None:
+            # urllib3 requires a bytes-like body. Python 2's json.dumps
+            # provides this natively, but Python 3 gives a Unicode string.
+            content_type = 'application/json'
+            body = complexjson.dumps(json)
+            if not isinstance(body, bytes):
+                body = body.encode('utf-8')
+
+        is_stream = all([
+            hasattr(data, '__iter__'),
+            not isinstance(data, (basestring, list, tuple, Mapping))
+        ])
+
+        if is_stream:
+            try:
+                length = super_len(data)
+            except (TypeError, AttributeError, UnsupportedOperation):
+                length = None
+
+            body = data
+
+            if getattr(body, 'tell', None) is not None:
+                # Record the current file position before reading.
+                # This will allow us to rewind a file in the event
+                # of a redirect.
+                try:
+                    self._body_position = body.tell()
+                except (IOError, OSError):
+                    # This differentiates from None, allowing us to catch
+                    # a failed `tell()` later when trying to rewind the body
+                    self._body_position = object()
+
+            if files:
+                raise NotImplementedError('Streamed bodies and files are mutually exclusive.')
+
+            if length:
+                self.headers['Content-Length'] = builtin_str(length)
+            else:
+                self.headers['Transfer-Encoding'] = 'chunked'
+        else:
+            # Multi-part file uploads.
+            if files:
+                (body, content_type) = self._encode_files(files, data)
+            else:
+                if data:
+                    body = self._encode_params(data)
+                    if isinstance(data, basestring) or hasattr(data, 'read'):
+                        content_type = None
+                    else:
+                        content_type = 'application/x-www-form-urlencoded'
+
+            self.prepare_content_length(body)
+
+            # Add content-type if it wasn't explicitly provided.
+            if content_type and ('content-type' not in self.headers):
+                self.headers['Content-Type'] = content_type
+
+        self.body = body
+
+    def prepare_content_length(self, body):
+        """Prepare Content-Length header based on request method and body"""
+        if body is not None:
+            length = super_len(body)
+            if length:
+                # If length exists, set it. Otherwise, we fallback
+                # to Transfer-Encoding: chunked.
+                self.headers['Content-Length'] = builtin_str(length)
+        elif self.method not in ('GET', 'HEAD') and self.headers.get('Content-Length') is None:
+            # Set Content-Length to 0 for methods that can have a body
+            # but don't provide one. (i.e. not GET or HEAD)
+            self.headers['Content-Length'] = '0'
+
+    def prepare_auth(self, auth, url=''):
+        """Prepares the given HTTP auth data."""
+
+        # If no Auth is explicitly provided, extract it from the URL first.
+        if auth is None:
+            url_auth = get_auth_from_url(self.url)
+            auth = url_auth if any(url_auth) else None
+
+        if auth:
+            if isinstance(auth, tuple) and len(auth) == 2:
+                # special-case basic HTTP auth
+                auth = HTTPBasicAuth(*auth)
+
+            # Allow auth to make its changes.
+            r = auth(self)
+
+            # Update self to reflect the auth changes.
+            self.__dict__.update(r.__dict__)
+
+            # Recompute Content-Length
+            self.prepare_content_length(self.body)
+
+    def prepare_cookies(self, cookies):
+        """Prepares the given HTTP cookie data.
+
+        This function eventually generates a ``Cookie`` header from the
+        given cookies using cookielib. Due to cookielib's design, the header
+        will not be regenerated if it already exists, meaning this function
+        can only be called once for the life of the
+        :class:`PreparedRequest <PreparedRequest>` object. Any subsequent calls
+        to ``prepare_cookies`` will have no actual effect, unless the "Cookie"
+        header is removed beforehand.
+        """
+        if isinstance(cookies, cookielib.CookieJar):
+            self._cookies = cookies
+        else:
+            self._cookies = cookiejar_from_dict(cookies)
+
+        cookie_header = get_cookie_header(self._cookies, self)
+        if cookie_header is not None:
+            self.headers['Cookie'] = cookie_header
+
+    def prepare_hooks(self, hooks):
+        """Prepares the given hooks."""
+        # hooks can be passed as None to the prepare method and to this
+        # method. To prevent iterating over None, simply use an empty list
+        # if hooks is False-y
+        hooks = hooks or []
+        for event in hooks:
+            self.register_hook(event, hooks[event])
+
+
+class Response(object):
+    """The :class:`Response <Response>` object, which contains a
+    server's response to an HTTP request.
+    """
+
+    __attrs__ = [
+        '_content', 'status_code', 'headers', 'url', 'history',
+        'encoding', 'reason', 'cookies', 'elapsed', 'request'
+    ]
+
+    def __init__(self):
+        self._content = False
+        self._content_consumed = False
+        self._next = None
+
+        #: Integer Code of responded HTTP Status, e.g. 404 or 200.
+        self.status_code = None
+
+        #: Case-insensitive Dictionary of Response Headers.
+        #: For example, ``headers['content-encoding']`` will return the
+        #: value of a ``'Content-Encoding'`` response header.
+        self.headers = CaseInsensitiveDict()
+
+        #: File-like object representation of response (for advanced usage).
+        #: Use of ``raw`` requires that ``stream=True`` be set on the request.
+        #: This requirement does not apply for use internally to Requests.
+        self.raw = None
+
+        #: Final URL location of Response.
+        self.url = None
+
+        #: Encoding to decode with when accessing r.text.
+        self.encoding = None
+
+        #: A list of :class:`Response <Response>` objects from
+        #: the history of the Request. Any redirect responses will end
+        #: up here. The list is sorted from the oldest to the most recent request.
+        self.history = []
+
+        #: Textual reason of responded HTTP Status, e.g. "Not Found" or "OK".
+        self.reason = None
+
+        #: A CookieJar of Cookies the server sent back.
+        self.cookies = cookiejar_from_dict({})
+
+        #: The amount of time elapsed between sending the request
+        #: and the arrival of the response (as a timedelta).
+        #: This property specifically measures the time taken between sending
+        #: the first byte of the request and finishing parsing the headers. It
+        #: is therefore unaffected by consuming the response content or the
+        #: value of the ``stream`` keyword argument.
+        self.elapsed = datetime.timedelta(0)
+
+        #: The :class:`PreparedRequest <PreparedRequest>` object to which this
+        #: is a response.
+        self.request = None
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
+    def __getstate__(self):
+        # Consume everything; accessing the content attribute makes
+        # sure the content has been fully read.
+        if not self._content_consumed:
+            self.content
+
+        return {attr: getattr(self, attr, None) for attr in self.__attrs__}
+
+    def __setstate__(self, state):
+        for name, value in state.items():
+            setattr(self, name, value)
+
+        # pickled objects do not have .raw
+        setattr(self, '_content_consumed', True)
+        setattr(self, 'raw', None)
+
+    def __repr__(self):
+        return '<Response [%s]>' % (self.status_code)
+
+    def __bool__(self):
+        """Returns True if :attr:`status_code` is less than 400.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code, is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
+        return self.ok
+
+    def __nonzero__(self):
+        """Returns True if :attr:`status_code` is less than 400.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code, is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
+        return self.ok
+
+    def __iter__(self):
+        """Allows you to use a response as an iterator."""
+        return self.iter_content(128)
+
+    @property
+    def ok(self):
+        """Returns True if :attr:`status_code` is less than 400, False if not.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
+        try:
+            self.raise_for_status()
+        except HTTPError:
+            return False
+        return True
+
+    @property
+    def is_redirect(self):
+        """True if this Response is a well-formed HTTP redirect that could have
+        been processed automatically (by :meth:`Session.resolve_redirects`).
+        """
+        return ('location' in self.headers and self.status_code in REDIRECT_STATI)
+
+    @property
+    def is_permanent_redirect(self):
+        """True if this Response one of the permanent versions of redirect."""
+        return ('location' in self.headers and self.status_code in (codes.moved_permanently, codes.permanent_redirect))
+
+    @property
+    def next(self):
+        """Returns a PreparedRequest for the next request in a redirect chain, if there is one."""
+        return self._next
+
+    @property
+    def apparent_encoding(self):
+        """The apparent encoding, provided by the chardet library."""
+        return chardet.detect(self.content)['encoding']
+
+    def iter_content(self, chunk_size=1, decode_unicode=False):
+        """Iterates over the response data.  When stream=True is set on the
+        request, this avoids reading the content at once into memory for
+        large responses.  The chunk size is the number of bytes it should
+        read into memory.  This is not necessarily the length of each item
+        returned as decoding can take place.
+
+        chunk_size must be of type int or None. A value of None will
+        function differently depending on the value of `stream`.
+        stream=True will read data as it arrives in whatever size the
+        chunks are received. If stream=False, data is returned as
+        a single chunk.
+
+        If decode_unicode is True, content will be decoded using the best
+        available encoding based on the response.
+        """
+
+        def generate():
+            # Special case for urllib3.
+            if hasattr(self.raw, 'stream'):
+                try:
+                    for chunk in self.raw.stream(chunk_size, decode_content=True):
+                        yield chunk
+                except ProtocolError as e:
+                    raise ChunkedEncodingError(e)
+                except DecodeError as e:
+                    raise ContentDecodingError(e)
+                except ReadTimeoutError as e:
+                    raise ConnectionError(e)
+            else:
+                # Standard file-like object.
+                while True:
+                    chunk = self.raw.read(chunk_size)
+                    if not chunk:
+                        break
+                    yield chunk
+
+            self._content_consumed = True
+
+        if self._content_consumed and isinstance(self._content, bool):
+            raise StreamConsumedError()
+        elif chunk_size is not None and not isinstance(chunk_size, int):
+            raise TypeError("chunk_size must be an int, it is instead a %s." % type(chunk_size))
+        # simulate reading small chunks of the content
+        reused_chunks = iter_slices(self._content, chunk_size)
+
+        stream_chunks = generate()
+
+        chunks = reused_chunks if self._content_consumed else stream_chunks
+
+        if decode_unicode:
+            chunks = stream_decode_response_unicode(chunks, self)
+
+        return chunks
+
+    def iter_lines(self, chunk_size=ITER_CHUNK_SIZE, decode_unicode=False, delimiter=None):
+        """Iterates over the response data, one line at a time.  When
+        stream=True is set on the request, this avoids reading the
+        content at once into memory for large responses.
+
+        .. note:: This method is not reentrant safe.
+        """
+
+        pending = None
+
+        for chunk in self.iter_content(chunk_size=chunk_size, decode_unicode=decode_unicode):
+
+            if pending is not None:
+                chunk = pending + chunk
+
+            if delimiter:
+                lines = chunk.split(delimiter)
+            else:
+                lines = chunk.splitlines()
+
+            if lines and lines[-1] and chunk and lines[-1][-1] == chunk[-1]:
+                pending = lines.pop()
+            else:
+                pending = None
+
+            for line in lines:
+                yield line
+
+        if pending is not None:
+            yield pending
+
+    @property
+    def content(self):
+        """Content of the response, in bytes."""
+
+        if self._content is False:
+            # Read the contents.
+            if self._content_consumed:
+                raise RuntimeError(
+                    'The content for this response was already consumed')
+
+            if self.status_code == 0 or self.raw is None:
+                self._content = None
+            else:
+                self._content = b''.join(self.iter_content(CONTENT_CHUNK_SIZE)) or b''
+
+        self._content_consumed = True
+        # don't need to release the connection; that's been handled by urllib3
+        # since we exhausted the data.
+        return self._content
+
+    @property
+    def text(self):
+        """Content of the response, in unicode.
+
+        If Response.encoding is None, encoding will be guessed using
+        ``chardet``.
+
+        The encoding of the response content is determined based solely on HTTP
+        headers, following RFC 2616 to the letter. If you can take advantage of
+        non-HTTP knowledge to make a better guess at the encoding, you should
+        set ``r.encoding`` appropriately before accessing this property.
+        """
+
+        # Try charset from content-type
+        content = None
+        encoding = self.encoding
+
+        if not self.content:
+            return str('')
+
+        # Fallback to auto-detected encoding.
+        if self.encoding is None:
+            encoding = self.apparent_encoding
+
+        # Decode unicode from given encoding.
+        try:
+            content = str(self.content, encoding, errors='replace')
+        except (LookupError, TypeError):
+            # A LookupError is raised if the encoding was not found which could
+            # indicate a misspelling or similar mistake.
+            #
+            # A TypeError can be raised if encoding is None
+            #
+            # So we try blindly encoding.
+            content = str(self.content, errors='replace')
+
+        return content
+
+    def json(self, **kwargs):
+        r"""Returns the json-encoded content of a response, if any.
+
+        :param \*\*kwargs: Optional arguments that ``json.loads`` takes.
+        :raises ValueError: If the response body does not contain valid json.
+        """
+
+        if not self.encoding and self.content and len(self.content) > 3:
+            # No encoding set. JSON RFC 4627 section 3 states we should expect
+            # UTF-8, -16 or -32. Detect which one to use; If the detection or
+            # decoding fails, fall back to `self.text` (using chardet to make
+            # a best guess).
+            encoding = guess_json_utf(self.content)
+            if encoding is not None:
+                try:
+                    return complexjson.loads(
+                        self.content.decode(encoding), **kwargs
+                    )
+                except UnicodeDecodeError:
+                    # Wrong UTF codec detected; usually because it's not UTF-8
+                    # but some other 8-bit codec.  This is an RFC violation,
+                    # and the server didn't bother to tell us what codec *was*
+                    # used.
+                    pass
+        return complexjson.loads(self.text, **kwargs)
+
+    @property
+    def links(self):
+        """Returns the parsed header links of the response, if any."""
+
+        header = self.headers.get('link')
+
+        # l = MultiDict()
+        l = {}
+
+        if header:
+            links = parse_header_links(header)
+
+            for link in links:
+                key = link.get('rel') or link.get('url')
+                l[key] = link
+
+        return l
+
+    def raise_for_status(self):
+        """Raises :class:`HTTPError`, if one occurred."""
+
+        http_error_msg = ''
+        if isinstance(self.reason, bytes):
+            # We attempt to decode utf-8 first because some servers
+            # choose to localize their reason strings. If the string
+            # isn't utf-8, we fall back to iso-8859-1 for all other
+            # encodings. (See PR #3538)
+            try:
+                reason = self.reason.decode('utf-8')
+            except UnicodeDecodeError:
+                reason = self.reason.decode('iso-8859-1')
+        else:
+            reason = self.reason
+
+        if 400 <= self.status_code < 500:
+            http_error_msg = u'%s Client Error: %s for url: %s' % (self.status_code, reason, self.url)
+
+        elif 500 <= self.status_code < 600:
+            http_error_msg = u'%s Server Error: %s for url: %s' % (self.status_code, reason, self.url)
+
+        if http_error_msg:
+            raise HTTPError(http_error_msg, response=self)
+
+    def close(self):
+        """Releases the connection back to the pool. Once this method has been
+        called the underlying ``raw`` object must not be accessed again.
+
+        *Note: Should not normally need to be called explicitly.*
+        """
+        if not self._content_consumed:
+            self.raw.close()
+
+        release_conn = getattr(self.raw, 'release_conn', None)
+        if release_conn is not None:
+            release_conn()

venv/Lib/site-packages/pip/_vendor/requests/packages.py

@@ -0,0 +1,16 @@
+import sys
+
+# This code exists for backwards compatibility reasons.
+# I don't like it either. Just look the other way. :)
+
+for package in ('urllib3', 'idna', 'chardet'):
+    vendored_package = "pip._vendor." + package
+    locals()[package] = __import__(vendored_package)
+    # This traversal is apparently necessary such that the identities are
+    # preserved (requests.packages.urllib3.* is urllib3.*)
+    for mod in list(sys.modules):
+        if mod == vendored_package or mod.startswith(vendored_package + '.'):
+            unprefixed_mod = mod[len("pip._vendor."):]
+            sys.modules['pip._vendor.requests.packages.' + unprefixed_mod] = sys.modules[mod]
+
+# Kinda cool, though, right?

venv/Lib/site-packages/pip/_vendor/requests/sessions.py

@@ -0,0 +1,769 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.session
+~~~~~~~~~~~~~~~~
+
+This module provides a Session object to manage and persist settings across
+requests (cookies, auth, proxies).
+"""
+import os
+import sys
+import time
+from datetime import timedelta
+from collections import OrderedDict
+
+from .auth import _basic_auth_str
+from .compat import cookielib, is_py3, urljoin, urlparse, Mapping
+from .cookies import (
+    cookiejar_from_dict, extract_cookies_to_jar, RequestsCookieJar, merge_cookies)
+from .models import Request, PreparedRequest, DEFAULT_REDIRECT_LIMIT
+from .hooks import default_hooks, dispatch_hook
+from ._internal_utils import to_native_string
+from .utils import to_key_val_list, default_headers, DEFAULT_PORTS
+from .exceptions import (
+    TooManyRedirects, InvalidSchema, ChunkedEncodingError, ContentDecodingError)
+
+from .structures import CaseInsensitiveDict
+from .adapters import HTTPAdapter
+
+from .utils import (
+    requote_uri, get_environ_proxies, get_netrc_auth, should_bypass_proxies,
+    get_auth_from_url, rewind_body
+)
+
+from .status_codes import codes
+
+# formerly defined here, reexposed here for backward compatibility
+from .models import REDIRECT_STATI
+
+# Preferred clock, based on which one is more accurate on a given system.
+if sys.platform == 'win32':
+    try:  # Python 3.4+
+        preferred_clock = time.perf_counter
+    except AttributeError:  # Earlier than Python 3.
+        preferred_clock = time.clock
+else:
+    preferred_clock = time.time
+
+
+def merge_setting(request_setting, session_setting, dict_class=OrderedDict):
+    """Determines appropriate setting for a given request, taking into account
+    the explicit setting on that request, and the setting in the session. If a
+    setting is a dictionary, they will be merged together using `dict_class`
+    """
+
+    if session_setting is None:
+        return request_setting
+
+    if request_setting is None:
+        return session_setting
+
+    # Bypass if not a dictionary (e.g. verify)
+    if not (
+            isinstance(session_setting, Mapping) and
+            isinstance(request_setting, Mapping)
+    ):
+        return request_setting
+
+    merged_setting = dict_class(to_key_val_list(session_setting))
+    merged_setting.update(to_key_val_list(request_setting))
+
+    # Remove keys that are set to None. Extract keys first to avoid altering
+    # the dictionary during iteration.
+    none_keys = [k for (k, v) in merged_setting.items() if v is None]
+    for key in none_keys:
+        del merged_setting[key]
+
+    return merged_setting
+
+
+def merge_hooks(request_hooks, session_hooks, dict_class=OrderedDict):
+    """Properly merges both requests and session hooks.
+
+    This is necessary because when request_hooks == {'response': []}, the
+    merge breaks Session hooks entirely.
+    """
+    if session_hooks is None or session_hooks.get('response') == []:
+        return request_hooks
+
+    if request_hooks is None or request_hooks.get('response') == []:
+        return session_hooks
+
+    return merge_setting(request_hooks, session_hooks, dict_class)
+
+
+class SessionRedirectMixin(object):
+
+    def get_redirect_target(self, resp):
+        """Receives a Response. Returns a redirect URI or ``None``"""
+        # Due to the nature of how requests processes redirects this method will
+        # be called at least once upon the original response and at least twice
+        # on each subsequent redirect response (if any).
+        # If a custom mixin is used to handle this logic, it may be advantageous
+        # to cache the redirect location onto the response object as a private
+        # attribute.
+        if resp.is_redirect:
+            location = resp.headers['location']
+            # Currently the underlying http module on py3 decode headers
+            # in latin1, but empirical evidence suggests that latin1 is very
+            # rarely used with non-ASCII characters in HTTP headers.
+            # It is more likely to get UTF8 header rather than latin1.
+            # This causes incorrect handling of UTF8 encoded location headers.
+            # To solve this, we re-encode the location in latin1.
+            if is_py3:
+                location = location.encode('latin1')
+            return to_native_string(location, 'utf8')
+        return None
+
+    def should_strip_auth(self, old_url, new_url):
+        """Decide whether Authorization header should be removed when redirecting"""
+        old_parsed = urlparse(old_url)
+        new_parsed = urlparse(new_url)
+        if old_parsed.hostname != new_parsed.hostname:
+            return True
+        # Special case: allow http -> https redirect when using the standard
+        # ports. This isn't specified by RFC 7235, but is kept to avoid
+        # breaking backwards compatibility with older versions of requests
+        # that allowed any redirects on the same host.
+        if (old_parsed.scheme == 'http' and old_parsed.port in (80, None)
+                and new_parsed.scheme == 'https' and new_parsed.port in (443, None)):
+            return False
+
+        # Handle default port usage corresponding to scheme.
+        changed_port = old_parsed.port != new_parsed.port
+        changed_scheme = old_parsed.scheme != new_parsed.scheme
+        default_port = (DEFAULT_PORTS.get(old_parsed.scheme, None), None)
+        if (not changed_scheme and old_parsed.port in default_port
+                and new_parsed.port in default_port):
+            return False
+
+        # Standard case: root URI must match
+        return changed_port or changed_scheme
+
+    def resolve_redirects(self, resp, req, stream=False, timeout=None,
+                          verify=True, cert=None, proxies=None, yield_requests=False, **adapter_kwargs):
+        """Receives a Response. Returns a generator of Responses or Requests."""
+
+        hist = []  # keep track of history
+
+        url = self.get_redirect_target(resp)
+        previous_fragment = urlparse(req.url).fragment
+        while url:
+            prepared_request = req.copy()
+
+            # Update history and keep track of redirects.
+            # resp.history must ignore the original request in this loop
+            hist.append(resp)
+            resp.history = hist[1:]
+
+            try:
+                resp.content  # Consume socket so it can be released
+            except (ChunkedEncodingError, ContentDecodingError, RuntimeError):
+                resp.raw.read(decode_content=False)
+
+            if len(resp.history) >= self.max_redirects:
+                raise TooManyRedirects('Exceeded {} redirects.'.format(self.max_redirects), response=resp)
+
+            # Release the connection back into the pool.
+            resp.close()
+
+            # Handle redirection without scheme (see: RFC 1808 Section 4)
+            if url.startswith('//'):
+                parsed_rurl = urlparse(resp.url)
+                url = ':'.join([to_native_string(parsed_rurl.scheme), url])
+
+            # Normalize url case and attach previous fragment if needed (RFC 7231 7.1.2)
+            parsed = urlparse(url)
+            if parsed.fragment == '' and previous_fragment:
+                parsed = parsed._replace(fragment=previous_fragment)
+            elif parsed.fragment:
+                previous_fragment = parsed.fragment
+            url = parsed.geturl()
+
+            # Facilitate relative 'location' headers, as allowed by RFC 7231.
+            # (e.g. '/path/to/resource' instead of 'http://domain.tld/path/to/resource')
+            # Compliant with RFC3986, we percent encode the url.
+            if not parsed.netloc:
+                url = urljoin(resp.url, requote_uri(url))
+            else:
+                url = requote_uri(url)
+
+            prepared_request.url = to_native_string(url)
+
+            self.rebuild_method(prepared_request, resp)
+
+            # https://github.com/psf/requests/issues/1084
+            if resp.status_code not in (codes.temporary_redirect, codes.permanent_redirect):
+                # https://github.com/psf/requests/issues/3490
+                purged_headers = ('Content-Length', 'Content-Type', 'Transfer-Encoding')
+                for header in purged_headers:
+                    prepared_request.headers.pop(header, None)
+                prepared_request.body = None
+
+            headers = prepared_request.headers
+            headers.pop('Cookie', None)
+
+            # Extract any cookies sent on the response to the cookiejar
+            # in the new request. Because we've mutated our copied prepared
+            # request, use the old one that we haven't yet touched.
+            extract_cookies_to_jar(prepared_request._cookies, req, resp.raw)
+            merge_cookies(prepared_request._cookies, self.cookies)
+            prepared_request.prepare_cookies(prepared_request._cookies)
+
+            # Rebuild auth and proxy information.
+            proxies = self.rebuild_proxies(prepared_request, proxies)
+            self.rebuild_auth(prepared_request, resp)
+
+            # A failed tell() sets `_body_position` to `object()`. This non-None
+            # value ensures `rewindable` will be True, allowing us to raise an
+            # UnrewindableBodyError, instead of hanging the connection.
+            rewindable = (
+                prepared_request._body_position is not None and
+                ('Content-Length' in headers or 'Transfer-Encoding' in headers)
+            )
+
+            # Attempt to rewind consumed file-like object.
+            if rewindable:
+                rewind_body(prepared_request)
+
+            # Override the original request.
+            req = prepared_request
+
+            if yield_requests:
+                yield req
+            else:
+
+                resp = self.send(
+                    req,
+                    stream=stream,
+                    timeout=timeout,
+                    verify=verify,
+                    cert=cert,
+                    proxies=proxies,
+                    allow_redirects=False,
+                    **adapter_kwargs
+                )
+
+                extract_cookies_to_jar(self.cookies, prepared_request, resp.raw)
+
+                # extract redirect url, if any, for the next loop
+                url = self.get_redirect_target(resp)
+                yield resp
+
+    def rebuild_auth(self, prepared_request, response):
+        """When being redirected we may want to strip authentication from the
+        request to avoid leaking credentials. This method intelligently removes
+        and reapplies authentication where possible to avoid credential loss.
+        """
+        headers = prepared_request.headers
+        url = prepared_request.url
+
+        if 'Authorization' in headers and self.should_strip_auth(response.request.url, url):
+            # If we get redirected to a new host, we should strip out any
+            # authentication headers.
+            del headers['Authorization']
+
+        # .netrc might have more auth for us on our new host.
+        new_auth = get_netrc_auth(url) if self.trust_env else None
+        if new_auth is not None:
+            prepared_request.prepare_auth(new_auth)
+
+
+    def rebuild_proxies(self, prepared_request, proxies):
+        """This method re-evaluates the proxy configuration by considering the
+        environment variables. If we are redirected to a URL covered by
+        NO_PROXY, we strip the proxy configuration. Otherwise, we set missing
+        proxy keys for this URL (in case they were stripped by a previous
+        redirect).
+
+        This method also replaces the Proxy-Authorization header where
+        necessary.
+
+        :rtype: dict
+        """
+        proxies = proxies if proxies is not None else {}
+        headers = prepared_request.headers
+        url = prepared_request.url
+        scheme = urlparse(url).scheme
+        new_proxies = proxies.copy()
+        no_proxy = proxies.get('no_proxy')
+
+        bypass_proxy = should_bypass_proxies(url, no_proxy=no_proxy)
+        if self.trust_env and not bypass_proxy:
+            environ_proxies = get_environ_proxies(url, no_proxy=no_proxy)
+
+            proxy = environ_proxies.get(scheme, environ_proxies.get('all'))
+
+            if proxy:
+                new_proxies.setdefault(scheme, proxy)
+
+        if 'Proxy-Authorization' in headers:
+            del headers['Proxy-Authorization']
+
+        try:
+            username, password = get_auth_from_url(new_proxies[scheme])
+        except KeyError:
+            username, password = None, None
+
+        if username and password:
+            headers['Proxy-Authorization'] = _basic_auth_str(username, password)
+
+        return new_proxies
+
+    def rebuild_method(self, prepared_request, response):
+        """When being redirected we may want to change the method of the request
+        based on certain specs or browser behavior.
+        """
+        method = prepared_request.method
+
+        # https://tools.ietf.org/html/rfc7231#section-6.4.4
+        if response.status_code == codes.see_other and method != 'HEAD':
+            method = 'GET'
+
+        # Do what the browsers do, despite standards...
+        # First, turn 302s into GETs.
+        if response.status_code == codes.found and method != 'HEAD':
+            method = 'GET'
+
+        # Second, if a POST is responded to with a 301, turn it into a GET.
+        # This bizarre behaviour is explained in Issue 1704.
+        if response.status_code == codes.moved and method == 'POST':
+            method = 'GET'
+
+        prepared_request.method = method
+
+
+class Session(SessionRedirectMixin):
+    """A Requests session.
+
+    Provides cookie persistence, connection-pooling, and configuration.
+
+    Basic Usage::
+
+      >>> import requests
+      >>> s = requests.Session()
+      >>> s.get('https://httpbin.org/get')
+      <Response [200]>
+
+    Or as a context manager::
+
+      >>> with requests.Session() as s:
+      ...     s.get('https://httpbin.org/get')
+      <Response [200]>
+    """
+
+    __attrs__ = [
+        'headers', 'cookies', 'auth', 'proxies', 'hooks', 'params', 'verify',
+        'cert', 'adapters', 'stream', 'trust_env',
+        'max_redirects',
+    ]
+
+    def __init__(self):
+
+        #: A case-insensitive dictionary of headers to be sent on each
+        #: :class:`Request <Request>` sent from this
+        #: :class:`Session <Session>`.
+        self.headers = default_headers()
+
+        #: Default Authentication tuple or object to attach to
+        #: :class:`Request <Request>`.
+        self.auth = None
+
+        #: Dictionary mapping protocol or protocol and host to the URL of the proxy
+        #: (e.g. {'http': 'foo.bar:3128', 'http://host.name': 'foo.bar:4012'}) to
+        #: be used on each :class:`Request <Request>`.
+        self.proxies = {}
+
+        #: Event-handling hooks.
+        self.hooks = default_hooks()
+
+        #: Dictionary of querystring data to attach to each
+        #: :class:`Request <Request>`. The dictionary values may be lists for
+        #: representing multivalued query parameters.
+        self.params = {}
+
+        #: Stream response content default.
+        self.stream = False
+
+        #: SSL Verification default.
+        self.verify = True
+
+        #: SSL client certificate default, if String, path to ssl client
+        #: cert file (.pem). If Tuple, ('cert', 'key') pair.
+        self.cert = None
+
+        #: Maximum number of redirects allowed. If the request exceeds this
+        #: limit, a :class:`TooManyRedirects` exception is raised.
+        #: This defaults to requests.models.DEFAULT_REDIRECT_LIMIT, which is
+        #: 30.
+        self.max_redirects = DEFAULT_REDIRECT_LIMIT
+
+        #: Trust environment settings for proxy configuration, default
+        #: authentication and similar.
+        self.trust_env = True
+
+        #: A CookieJar containing all currently outstanding cookies set on this
+        #: session. By default it is a
+        #: :class:`RequestsCookieJar <requests.cookies.RequestsCookieJar>`, but
+        #: may be any other ``cookielib.CookieJar`` compatible object.
+        self.cookies = cookiejar_from_dict({})
+
+        # Default connection adapters.
+        self.adapters = OrderedDict()
+        self.mount('https://', HTTPAdapter())
+        self.mount('http://', HTTPAdapter())
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
+    def prepare_request(self, request):
+        """Constructs a :class:`PreparedRequest <PreparedRequest>` for
+        transmission and returns it. The :class:`PreparedRequest` has settings
+        merged from the :class:`Request <Request>` instance and those of the
+        :class:`Session`.
+
+        :param request: :class:`Request` instance to prepare with this
+            session's settings.
+        :rtype: requests.PreparedRequest
+        """
+        cookies = request.cookies or {}
+
+        # Bootstrap CookieJar.
+        if not isinstance(cookies, cookielib.CookieJar):
+            cookies = cookiejar_from_dict(cookies)
+
+        # Merge with session cookies
+        merged_cookies = merge_cookies(
+            merge_cookies(RequestsCookieJar(), self.cookies), cookies)
+
+        # Set environment's basic authentication if not explicitly set.
+        auth = request.auth
+        if self.trust_env and not auth and not self.auth:
+            auth = get_netrc_auth(request.url)
+
+        p = PreparedRequest()
+        p.prepare(
+            method=request.method.upper(),
+            url=request.url,
+            files=request.files,
+            data=request.data,
+            json=request.json,
+            headers=merge_setting(request.headers, self.headers, dict_class=CaseInsensitiveDict),
+            params=merge_setting(request.params, self.params),
+            auth=merge_setting(auth, self.auth),
+            cookies=merged_cookies,
+            hooks=merge_hooks(request.hooks, self.hooks),
+        )
+        return p
+
+    def request(self, method, url,
+            params=None, data=None, headers=None, cookies=None, files=None,
+            auth=None, timeout=None, allow_redirects=True, proxies=None,
+            hooks=None, stream=None, verify=None, cert=None, json=None):
+        """Constructs a :class:`Request <Request>`, prepares it and sends it.
+        Returns :class:`Response <Response>` object.
+
+        :param method: method for the new :class:`Request` object.
+        :param url: URL for the new :class:`Request` object.
+        :param params: (optional) Dictionary or bytes to be sent in the query
+            string for the :class:`Request`.
+        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+            object to send in the body of the :class:`Request`.
+        :param json: (optional) json to send in the body of the
+            :class:`Request`.
+        :param headers: (optional) Dictionary of HTTP Headers to send with the
+            :class:`Request`.
+        :param cookies: (optional) Dict or CookieJar object to send with the
+            :class:`Request`.
+        :param files: (optional) Dictionary of ``'filename': file-like-objects``
+            for multipart encoding upload.
+        :param auth: (optional) Auth tuple or callable to enable
+            Basic/Digest/Custom HTTP Auth.
+        :param timeout: (optional) How long to wait for the server to send
+            data before giving up, as a float, or a :ref:`(connect timeout,
+            read timeout) <timeouts>` tuple.
+        :type timeout: float or tuple
+        :param allow_redirects: (optional) Set to True by default.
+        :type allow_redirects: bool
+        :param proxies: (optional) Dictionary mapping protocol or protocol and
+            hostname to the URL of the proxy.
+        :param stream: (optional) whether to immediately download the response
+            content. Defaults to ``False``.
+        :param verify: (optional) Either a boolean, in which case it controls whether we verify
+            the server's TLS certificate, or a string, in which case it must be a path
+            to a CA bundle to use. Defaults to ``True``.
+        :param cert: (optional) if String, path to ssl client cert file (.pem).
+            If Tuple, ('cert', 'key') pair.
+        :rtype: requests.Response
+        """
+        # Create the Request.
+        req = Request(
+            method=method.upper(),
+            url=url,
+            headers=headers,
+            files=files,
+            data=data or {},
+            json=json,
+            params=params or {},
+            auth=auth,
+            cookies=cookies,
+            hooks=hooks,
+        )
+        prep = self.prepare_request(req)
+
+        proxies = proxies or {}
+
+        settings = self.merge_environment_settings(
+            prep.url, proxies, stream, verify, cert
+        )
+
+        # Send the request.
+        send_kwargs = {
+            'timeout': timeout,
+            'allow_redirects': allow_redirects,
+        }
+        send_kwargs.update(settings)
+        resp = self.send(prep, **send_kwargs)
+
+        return resp
+
+    def get(self, url, **kwargs):
+        r"""Sends a GET request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        kwargs.setdefault('allow_redirects', True)
+        return self.request('GET', url, **kwargs)
+
+    def options(self, url, **kwargs):
+        r"""Sends a OPTIONS request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        kwargs.setdefault('allow_redirects', True)
+        return self.request('OPTIONS', url, **kwargs)
+
+    def head(self, url, **kwargs):
+        r"""Sends a HEAD request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        kwargs.setdefault('allow_redirects', False)
+        return self.request('HEAD', url, **kwargs)
+
+    def post(self, url, data=None, json=None, **kwargs):
+        r"""Sends a POST request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+            object to send in the body of the :class:`Request`.
+        :param json: (optional) json to send in the body of the :class:`Request`.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        return self.request('POST', url, data=data, json=json, **kwargs)
+
+    def put(self, url, data=None, **kwargs):
+        r"""Sends a PUT request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+            object to send in the body of the :class:`Request`.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        return self.request('PUT', url, data=data, **kwargs)
+
+    def patch(self, url, data=None, **kwargs):
+        r"""Sends a PATCH request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
+            object to send in the body of the :class:`Request`.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        return self.request('PATCH', url, data=data, **kwargs)
+
+    def delete(self, url, **kwargs):
+        r"""Sends a DELETE request. Returns :class:`Response` object.
+
+        :param url: URL for the new :class:`Request` object.
+        :param \*\*kwargs: Optional arguments that ``request`` takes.
+        :rtype: requests.Response
+        """
+
+        return self.request('DELETE', url, **kwargs)
+
+    def send(self, request, **kwargs):
+        """Send a given PreparedRequest.
+
+        :rtype: requests.Response
+        """
+        # Set defaults that the hooks can utilize to ensure they always have
+        # the correct parameters to reproduce the previous request.
+        kwargs.setdefault('stream', self.stream)
+        kwargs.setdefault('verify', self.verify)
+        kwargs.setdefault('cert', self.cert)
+        kwargs.setdefault('proxies', self.proxies)
+
+        # It's possible that users might accidentally send a Request object.
+        # Guard against that specific failure case.
+        if isinstance(request, Request):
+            raise ValueError('You can only send PreparedRequests.')
+
+        # Set up variables needed for resolve_redirects and dispatching of hooks
+        allow_redirects = kwargs.pop('allow_redirects', True)
+        stream = kwargs.get('stream')
+        hooks = request.hooks
+
+        # Get the appropriate adapter to use
+        adapter = self.get_adapter(url=request.url)
+
+        # Start time (approximately) of the request
+        start = preferred_clock()
+
+        # Send the request
+        r = adapter.send(request, **kwargs)
+
+        # Total elapsed time of the request (approximately)
+        elapsed = preferred_clock() - start
+        r.elapsed = timedelta(seconds=elapsed)
+
+        # Response manipulation hooks
+        r = dispatch_hook('response', hooks, r, **kwargs)
+
+        # Persist cookies
+        if r.history:
+
+            # If the hooks create history then we want those cookies too
+            for resp in r.history:
+                extract_cookies_to_jar(self.cookies, resp.request, resp.raw)
+
+        extract_cookies_to_jar(self.cookies, request, r.raw)
+
+        # Resolve redirects if allowed.
+        if allow_redirects:
+            # Redirect resolving generator.
+            gen = self.resolve_redirects(r, request, **kwargs)
+            history = [resp for resp in gen]
+        else:
+            history = []
+
+        # Shuffle things around if there's history.
+        if history:
+            # Insert the first (original) request at the start
+            history.insert(0, r)
+            # Get the last request made
+            r = history.pop()
+            r.history = history
+
+        # If redirects aren't being followed, store the response on the Request for Response.next().
+        if not allow_redirects:
+            try:
+                r._next = next(self.resolve_redirects(r, request, yield_requests=True, **kwargs))
+            except StopIteration:
+                pass
+
+        if not stream:
+            r.content
+
+        return r
+
+    def merge_environment_settings(self, url, proxies, stream, verify, cert):
+        """
+        Check the environment and merge it with some settings.
+
+        :rtype: dict
+        """
+        # Gather clues from the surrounding environment.
+        if self.trust_env:
+            # Set environment's proxies.
+            no_proxy = proxies.get('no_proxy') if proxies is not None else None
+            env_proxies = get_environ_proxies(url, no_proxy=no_proxy)
+            for (k, v) in env_proxies.items():
+                proxies.setdefault(k, v)
+
+            # Look for requests environment configuration and be compatible
+            # with cURL.
+            if verify is True or verify is None:
+                verify = (os.environ.get('REQUESTS_CA_BUNDLE') or
+                          os.environ.get('CURL_CA_BUNDLE'))
+
+        # Merge all the kwargs.
+        proxies = merge_setting(proxies, self.proxies)
+        stream = merge_setting(stream, self.stream)
+        verify = merge_setting(verify, self.verify)
+        cert = merge_setting(cert, self.cert)
+
+        return {'verify': verify, 'proxies': proxies, 'stream': stream,
+                'cert': cert}
+
+    def get_adapter(self, url):
+        """
+        Returns the appropriate connection adapter for the given URL.
+
+        :rtype: requests.adapters.BaseAdapter
+        """
+        for (prefix, adapter) in self.adapters.items():
+
+            if url.lower().startswith(prefix.lower()):
+                return adapter
+
+        # Nothing matches :-/
+        raise InvalidSchema("No connection adapters were found for {!r}".format(url))
+
+    def close(self):
+        """Closes all adapters and as such the session"""
+        for v in self.adapters.values():
+            v.close()
+
+    def mount(self, prefix, adapter):
+        """Registers a connection adapter to a prefix.
+
+        Adapters are sorted in descending order by prefix length.
+        """
+        self.adapters[prefix] = adapter
+        keys_to_move = [k for k in self.adapters if len(k) < len(prefix)]
+
+        for key in keys_to_move:
+            self.adapters[key] = self.adapters.pop(key)
+
+    def __getstate__(self):
+        state = {attr: getattr(self, attr, None) for attr in self.__attrs__}
+        return state
+
+    def __setstate__(self, state):
+        for attr, value in state.items():
+            setattr(self, attr, value)
+
+
+def session():
+    """
+    Returns a :class:`Session` for context-management.
+
+    .. deprecated:: 1.0.0
+
+        This method has been deprecated since version 1.0.0 and is only kept for
+        backwards compatibility. New code should use :class:`~requests.sessions.Session`
+        to create a session. This may be removed at a future date.
+
+    :rtype: Session
+    """
+    return Session()

venv/Lib/site-packages/pip/_vendor/requests/status_codes.py

@@ -0,0 +1,123 @@
+# -*- coding: utf-8 -*-
+
+r"""
+The ``codes`` object defines a mapping from common names for HTTP statuses
+to their numerical codes, accessible either as attributes or as dictionary
+items.
+
+Example::
+
+    >>> import requests
+    >>> requests.codes['temporary_redirect']
+    307
+    >>> requests.codes.teapot
+    418
+    >>> requests.codes['\o/']
+    200
+
+Some codes have multiple names, and both upper- and lower-case versions of
+the names are allowed. For example, ``codes.ok``, ``codes.OK``, and
+``codes.okay`` all correspond to the HTTP status code 200.
+"""
+
+from .structures import LookupDict
+
+_codes = {
+
+    # Informational.
+    100: ('continue',),
+    101: ('switching_protocols',),
+    102: ('processing',),
+    103: ('checkpoint',),
+    122: ('uri_too_long', 'request_uri_too_long'),
+    200: ('ok', 'okay', 'all_ok', 'all_okay', 'all_good', '\\o/', '✓'),
+    201: ('created',),
+    202: ('accepted',),
+    203: ('non_authoritative_info', 'non_authoritative_information'),
+    204: ('no_content',),
+    205: ('reset_content', 'reset'),
+    206: ('partial_content', 'partial'),
+    207: ('multi_status', 'multiple_status', 'multi_stati', 'multiple_stati'),
+    208: ('already_reported',),
+    226: ('im_used',),
+
+    # Redirection.
+    300: ('multiple_choices',),
+    301: ('moved_permanently', 'moved', '\\o-'),
+    302: ('found',),
+    303: ('see_other', 'other'),
+    304: ('not_modified',),
+    305: ('use_proxy',),
+    306: ('switch_proxy',),
+    307: ('temporary_redirect', 'temporary_moved', 'temporary'),
+    308: ('permanent_redirect',
+          'resume_incomplete', 'resume',),  # These 2 to be removed in 3.0
+
+    # Client Error.
+    400: ('bad_request', 'bad'),
+    401: ('unauthorized',),
+    402: ('payment_required', 'payment'),
+    403: ('forbidden',),
+    404: ('not_found', '-o-'),
+    405: ('method_not_allowed', 'not_allowed'),
+    406: ('not_acceptable',),
+    407: ('proxy_authentication_required', 'proxy_auth', 'proxy_authentication'),
+    408: ('request_timeout', 'timeout'),
+    409: ('conflict',),
+    410: ('gone',),
+    411: ('length_required',),
+    412: ('precondition_failed', 'precondition'),
+    413: ('request_entity_too_large',),
+    414: ('request_uri_too_large',),
+    415: ('unsupported_media_type', 'unsupported_media', 'media_type'),
+    416: ('requested_range_not_satisfiable', 'requested_range', 'range_not_satisfiable'),
+    417: ('expectation_failed',),
+    418: ('im_a_teapot', 'teapot', 'i_am_a_teapot'),
+    421: ('misdirected_request',),
+    422: ('unprocessable_entity', 'unprocessable'),
+    423: ('locked',),
+    424: ('failed_dependency', 'dependency'),
+    425: ('unordered_collection', 'unordered'),
+    426: ('upgrade_required', 'upgrade'),
+    428: ('precondition_required', 'precondition'),
+    429: ('too_many_requests', 'too_many'),
+    431: ('header_fields_too_large', 'fields_too_large'),
+    444: ('no_response', 'none'),
+    449: ('retry_with', 'retry'),
+    450: ('blocked_by_windows_parental_controls', 'parental_controls'),
+    451: ('unavailable_for_legal_reasons', 'legal_reasons'),
+    499: ('client_closed_request',),
+
+    # Server Error.
+    500: ('internal_server_error', 'server_error', '/o\\', '✗'),
+    501: ('not_implemented',),
+    502: ('bad_gateway',),
+    503: ('service_unavailable', 'unavailable'),
+    504: ('gateway_timeout',),
+    505: ('http_version_not_supported', 'http_version'),
+    506: ('variant_also_negotiates',),
+    507: ('insufficient_storage',),
+    509: ('bandwidth_limit_exceeded', 'bandwidth'),
+    510: ('not_extended',),
+    511: ('network_authentication_required', 'network_auth', 'network_authentication'),
+}
+
+codes = LookupDict(name='status_codes')
+
+def _init():
+    for code, titles in _codes.items():
+        for title in titles:
+            setattr(codes, title, code)
+            if not title.startswith(('\\', '/')):
+                setattr(codes, title.upper(), code)
+
+    def doc(code):
+        names = ', '.join('``%s``' % n for n in _codes[code])
+        return '* %d: %s' % (code, names)
+
+    global __doc__
+    __doc__ = (__doc__ + '\n' +
+               '\n'.join(doc(code) for code in sorted(_codes))
+               if __doc__ is not None else None)
+
+_init()

venv/Lib/site-packages/pip/_vendor/requests/structures.py

@@ -0,0 +1,105 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.structures
+~~~~~~~~~~~~~~~~~~~
+
+Data structures that power Requests.
+"""
+
+from collections import OrderedDict
+
+from .compat import Mapping, MutableMapping
+
+
+class CaseInsensitiveDict(MutableMapping):
+    """A case-insensitive ``dict``-like object.
+
+    Implements all methods and operations of
+    ``MutableMapping`` as well as dict's ``copy``. Also
+    provides ``lower_items``.
+
+    All keys are expected to be strings. The structure remembers the
+    case of the last key to be set, and ``iter(instance)``,
+    ``keys()``, ``items()``, ``iterkeys()``, and ``iteritems()``
+    will contain case-sensitive keys. However, querying and contains
+    testing is case insensitive::
+
+        cid = CaseInsensitiveDict()
+        cid['Accept'] = 'application/json'
+        cid['aCCEPT'] == 'application/json'  # True
+        list(cid) == ['Accept']  # True
+
+    For example, ``headers['content-encoding']`` will return the
+    value of a ``'Content-Encoding'`` response header, regardless
+    of how the header name was originally stored.
+
+    If the constructor, ``.update``, or equality comparison
+    operations are given keys that have equal ``.lower()``s, the
+    behavior is undefined.
+    """
+
+    def __init__(self, data=None, **kwargs):
+        self._store = OrderedDict()
+        if data is None:
+            data = {}
+        self.update(data, **kwargs)
+
+    def __setitem__(self, key, value):
+        # Use the lowercased key for lookups, but store the actual
+        # key alongside the value.
+        self._store[key.lower()] = (key, value)
+
+    def __getitem__(self, key):
+        return self._store[key.lower()][1]
+
+    def __delitem__(self, key):
+        del self._store[key.lower()]
+
+    def __iter__(self):
+        return (casedkey for casedkey, mappedvalue in self._store.values())
+
+    def __len__(self):
+        return len(self._store)
+
+    def lower_items(self):
+        """Like iteritems(), but with all lowercase keys."""
+        return (
+            (lowerkey, keyval[1])
+            for (lowerkey, keyval)
+            in self._store.items()
+        )
+
+    def __eq__(self, other):
+        if isinstance(other, Mapping):
+            other = CaseInsensitiveDict(other)
+        else:
+            return NotImplemented
+        # Compare insensitively
+        return dict(self.lower_items()) == dict(other.lower_items())
+
+    # Copy is required
+    def copy(self):
+        return CaseInsensitiveDict(self._store.values())
+
+    def __repr__(self):
+        return str(dict(self.items()))
+
+
+class LookupDict(dict):
+    """Dictionary lookup object."""
+
+    def __init__(self, name=None):
+        self.name = name
+        super(LookupDict, self).__init__()
+
+    def __repr__(self):
+        return '<lookup \'%s\'>' % (self.name)
+
+    def __getitem__(self, key):
+        # We allow fall-through here, so values default to None
+
+        return self.__dict__.get(key, None)
+
+    def get(self, key, default=None):
+        return self.__dict__.get(key, default)

venv/Lib/site-packages/pip/_vendor/requests/utils.py

@@ -0,0 +1,982 @@
+# -*- coding: utf-8 -*-
+
+"""
+requests.utils
+~~~~~~~~~~~~~~
+
+This module provides utility functions that are used within Requests
+that are also useful for external consumption.
+"""
+
+import codecs
+import contextlib
+import io
+import os
+import re
+import socket
+import struct
+import sys
+import tempfile
+import warnings
+import zipfile
+from collections import OrderedDict
+
+from .__version__ import __version__
+from . import certs
+# to_native_string is unused here, but imported here for backwards compatibility
+from ._internal_utils import to_native_string
+from .compat import parse_http_list as _parse_list_header
+from .compat import (
+    quote, urlparse, bytes, str, unquote, getproxies,
+    proxy_bypass, urlunparse, basestring, integer_types, is_py3,
+    proxy_bypass_environment, getproxies_environment, Mapping)
+from .cookies import cookiejar_from_dict
+from .structures import CaseInsensitiveDict
+from .exceptions import (
+    InvalidURL, InvalidHeader, FileModeWarning, UnrewindableBodyError)
+
+NETRC_FILES = ('.netrc', '_netrc')
+
+DEFAULT_CA_BUNDLE_PATH = certs.where()
+
+DEFAULT_PORTS = {'http': 80, 'https': 443}
+
+
+if sys.platform == 'win32':
+    # provide a proxy_bypass version on Windows without DNS lookups
+
+    def proxy_bypass_registry(host):
+        try:
+            if is_py3:
+                import winreg
+            else:
+                import _winreg as winreg
+        except ImportError:
+            return False
+
+        try:
+            internetSettings = winreg.OpenKey(winreg.HKEY_CURRENT_USER,
+                r'Software\Microsoft\Windows\CurrentVersion\Internet Settings')
+            # ProxyEnable could be REG_SZ or REG_DWORD, normalizing it
+            proxyEnable = int(winreg.QueryValueEx(internetSettings,
+                                              'ProxyEnable')[0])
+            # ProxyOverride is almost always a string
+            proxyOverride = winreg.QueryValueEx(internetSettings,
+                                                'ProxyOverride')[0]
+        except OSError:
+            return False
+        if not proxyEnable or not proxyOverride:
+            return False
+
+        # make a check value list from the registry entry: replace the
+        # '<local>' string by the localhost entry and the corresponding
+        # canonical entry.
+        proxyOverride = proxyOverride.split(';')
+        # now check if we match one of the registry values.
+        for test in proxyOverride:
+            if test == '<local>':
+                if '.' not in host:
+                    return True
+            test = test.replace(".", r"\.")     # mask dots
+            test = test.replace("*", r".*")     # change glob sequence
+            test = test.replace("?", r".")      # change glob char
+            if re.match(test, host, re.I):
+                return True
+        return False
+
+    def proxy_bypass(host):  # noqa
+        """Return True, if the host should be bypassed.
+
+        Checks proxy settings gathered from the environment, if specified,
+        or the registry.
+        """
+        if getproxies_environment():
+            return proxy_bypass_environment(host)
+        else:
+            return proxy_bypass_registry(host)
+
+
+def dict_to_sequence(d):
+    """Returns an internal sequence dictionary update."""
+
+    if hasattr(d, 'items'):
+        d = d.items()
+
+    return d
+
+
+def super_len(o):
+    total_length = None
+    current_position = 0
+
+    if hasattr(o, '__len__'):
+        total_length = len(o)
+
+    elif hasattr(o, 'len'):
+        total_length = o.len
+
+    elif hasattr(o, 'fileno'):
+        try:
+            fileno = o.fileno()
+        except io.UnsupportedOperation:
+            pass
+        else:
+            total_length = os.fstat(fileno).st_size
+
+            # Having used fstat to determine the file length, we need to
+            # confirm that this file was opened up in binary mode.
+            if 'b' not in o.mode:
+                warnings.warn((
+                    "Requests has determined the content-length for this "
+                    "request using the binary size of the file: however, the "
+                    "file has been opened in text mode (i.e. without the 'b' "
+                    "flag in the mode). This may lead to an incorrect "
+                    "content-length. In Requests 3.0, support will be removed "
+                    "for files in text mode."),
+                    FileModeWarning
+                )
+
+    if hasattr(o, 'tell'):
+        try:
+            current_position = o.tell()
+        except (OSError, IOError):
+            # This can happen in some weird situations, such as when the file
+            # is actually a special file descriptor like stdin. In this
+            # instance, we don't know what the length is, so set it to zero and
+            # let requests chunk it instead.
+            if total_length is not None:
+                current_position = total_length
+        else:
+            if hasattr(o, 'seek') and total_length is None:
+                # StringIO and BytesIO have seek but no useable fileno
+                try:
+                    # seek to end of file
+                    o.seek(0, 2)
+                    total_length = o.tell()
+
+                    # seek back to current position to support
+                    # partially read file-like objects
+                    o.seek(current_position or 0)
+                except (OSError, IOError):
+                    total_length = 0
+
+    if total_length is None:
+        total_length = 0
+
+    return max(0, total_length - current_position)
+
+
+def get_netrc_auth(url, raise_errors=False):
+    """Returns the Requests tuple auth for a given url from netrc."""
+
+    try:
+        from netrc import netrc, NetrcParseError
+
+        netrc_path = None
+
+        for f in NETRC_FILES:
+            try:
+                loc = os.path.expanduser('~/{}'.format(f))
+            except KeyError:
+                # os.path.expanduser can fail when $HOME is undefined and
+                # getpwuid fails. See https://bugs.python.org/issue20164 &
+                # https://github.com/psf/requests/issues/1846
+                return
+
+            if os.path.exists(loc):
+                netrc_path = loc
+                break
+
+        # Abort early if there isn't one.
+        if netrc_path is None:
+            return
+
+        ri = urlparse(url)
+
+        # Strip port numbers from netloc. This weird `if...encode`` dance is
+        # used for Python 3.2, which doesn't support unicode literals.
+        splitstr = b':'
+        if isinstance(url, str):
+            splitstr = splitstr.decode('ascii')
+        host = ri.netloc.split(splitstr)[0]
+
+        try:
+            _netrc = netrc(netrc_path).authenticators(host)
+            if _netrc:
+                # Return with login / password
+                login_i = (0 if _netrc[0] else 1)
+                return (_netrc[login_i], _netrc[2])
+        except (NetrcParseError, IOError):
+            # If there was a parsing error or a permissions issue reading the file,
+            # we'll just skip netrc auth unless explicitly asked to raise errors.
+            if raise_errors:
+                raise
+
+    # AppEngine hackiness.
+    except (ImportError, AttributeError):
+        pass
+
+
+def guess_filename(obj):
+    """Tries to guess the filename of the given object."""
+    name = getattr(obj, 'name', None)
+    if (name and isinstance(name, basestring) and name[0] != '<' and
+            name[-1] != '>'):
+        return os.path.basename(name)
+
+
+def extract_zipped_paths(path):
+    """Replace nonexistent paths that look like they refer to a member of a zip
+    archive with the location of an extracted copy of the target, or else
+    just return the provided path unchanged.
+    """
+    if os.path.exists(path):
+        # this is already a valid path, no need to do anything further
+        return path
+
+    # find the first valid part of the provided path and treat that as a zip archive
+    # assume the rest of the path is the name of a member in the archive
+    archive, member = os.path.split(path)
+    while archive and not os.path.exists(archive):
+        archive, prefix = os.path.split(archive)
+        member = '/'.join([prefix, member])
+
+    if not zipfile.is_zipfile(archive):
+        return path
+
+    zip_file = zipfile.ZipFile(archive)
+    if member not in zip_file.namelist():
+        return path
+
+    # we have a valid zip archive and a valid member of that archive
+    tmp = tempfile.gettempdir()
+    extracted_path = os.path.join(tmp, *member.split('/'))
+    if not os.path.exists(extracted_path):
+        extracted_path = zip_file.extract(member, path=tmp)
+
+    return extracted_path
+
+
+def from_key_val_list(value):
+    """Take an object and test to see if it can be represented as a
+    dictionary. Unless it can not be represented as such, return an
+    OrderedDict, e.g.,
+
+    ::
+
+        >>> from_key_val_list([('key', 'val')])
+        OrderedDict([('key', 'val')])
+        >>> from_key_val_list('string')
+        Traceback (most recent call last):
+        ...
+        ValueError: cannot encode objects that are not 2-tuples
+        >>> from_key_val_list({'key': 'val'})
+        OrderedDict([('key', 'val')])
+
+    :rtype: OrderedDict
+    """
+    if value is None:
+        return None
+
+    if isinstance(value, (str, bytes, bool, int)):
+        raise ValueError('cannot encode objects that are not 2-tuples')
+
+    return OrderedDict(value)
+
+
+def to_key_val_list(value):
+    """Take an object and test to see if it can be represented as a
+    dictionary. If it can be, return a list of tuples, e.g.,
+
+    ::
+
+        >>> to_key_val_list([('key', 'val')])
+        [('key', 'val')]
+        >>> to_key_val_list({'key': 'val'})
+        [('key', 'val')]
+        >>> to_key_val_list('string')
+        Traceback (most recent call last):
+        ...
+        ValueError: cannot encode objects that are not 2-tuples
+
+    :rtype: list
+    """
+    if value is None:
+        return None
+
+    if isinstance(value, (str, bytes, bool, int)):
+        raise ValueError('cannot encode objects that are not 2-tuples')
+
+    if isinstance(value, Mapping):
+        value = value.items()
+
+    return list(value)
+
+
+# From mitsuhiko/werkzeug (used with permission).
+def parse_list_header(value):
+    """Parse lists as described by RFC 2068 Section 2.
+
+    In particular, parse comma-separated lists where the elements of
+    the list may include quoted-strings.  A quoted-string could
+    contain a comma.  A non-quoted string could have quotes in the
+    middle.  Quotes are removed automatically after parsing.
+
+    It basically works like :func:`parse_set_header` just that items
+    may appear multiple times and case sensitivity is preserved.
+
+    The return value is a standard :class:`list`:
+
+    >>> parse_list_header('token, "quoted value"')
+    ['token', 'quoted value']
+
+    To create a header from the :class:`list` again, use the
+    :func:`dump_header` function.
+
+    :param value: a string with a list header.
+    :return: :class:`list`
+    :rtype: list
+    """
+    result = []
+    for item in _parse_list_header(value):
+        if item[:1] == item[-1:] == '"':
+            item = unquote_header_value(item[1:-1])
+        result.append(item)
+    return result
+
+
+# From mitsuhiko/werkzeug (used with permission).
+def parse_dict_header(value):
+    """Parse lists of key, value pairs as described by RFC 2068 Section 2 and
+    convert them into a python dict:
+
+    >>> d = parse_dict_header('foo="is a fish", bar="as well"')
+    >>> type(d) is dict
+    True
+    >>> sorted(d.items())
+    [('bar', 'as well'), ('foo', 'is a fish')]
+
+    If there is no value for a key it will be `None`:
+
+    >>> parse_dict_header('key_without_value')
+    {'key_without_value': None}
+
+    To create a header from the :class:`dict` again, use the
+    :func:`dump_header` function.
+
+    :param value: a string with a dict header.
+    :return: :class:`dict`
+    :rtype: dict
+    """
+    result = {}
+    for item in _parse_list_header(value):
+        if '=' not in item:
+            result[item] = None
+            continue
+        name, value = item.split('=', 1)
+        if value[:1] == value[-1:] == '"':
+            value = unquote_header_value(value[1:-1])
+        result[name] = value
+    return result
+
+
+# From mitsuhiko/werkzeug (used with permission).
+def unquote_header_value(value, is_filename=False):
+    r"""Unquotes a header value.  (Reversal of :func:`quote_header_value`).
+    This does not use the real unquoting but what browsers are actually
+    using for quoting.
+
+    :param value: the header value to unquote.
+    :rtype: str
+    """
+    if value and value[0] == value[-1] == '"':
+        # this is not the real unquoting, but fixing this so that the
+        # RFC is met will result in bugs with internet explorer and
+        # probably some other browsers as well.  IE for example is
+        # uploading files with "C:\foo\bar.txt" as filename
+        value = value[1:-1]
+
+        # if this is a filename and the starting characters look like
+        # a UNC path, then just return the value without quotes.  Using the
+        # replace sequence below on a UNC path has the effect of turning
+        # the leading double slash into a single slash and then
+        # _fix_ie_filename() doesn't work correctly.  See #458.
+        if not is_filename or value[:2] != '\\\\':
+            return value.replace('\\\\', '\\').replace('\\"', '"')
+    return value
+
+
+def dict_from_cookiejar(cj):
+    """Returns a key/value dictionary from a CookieJar.
+
+    :param cj: CookieJar object to extract cookies from.
+    :rtype: dict
+    """
+
+    cookie_dict = {}
+
+    for cookie in cj:
+        cookie_dict[cookie.name] = cookie.value
+
+    return cookie_dict
+
+
+def add_dict_to_cookiejar(cj, cookie_dict):
+    """Returns a CookieJar from a key/value dictionary.
+
+    :param cj: CookieJar to insert cookies into.
+    :param cookie_dict: Dict of key/values to insert into CookieJar.
+    :rtype: CookieJar
+    """
+
+    return cookiejar_from_dict(cookie_dict, cj)
+
+
+def get_encodings_from_content(content):
+    """Returns encodings from given content string.
+
+    :param content: bytestring to extract encodings from.
+    """
+    warnings.warn((
+        'In requests 3.0, get_encodings_from_content will be removed. For '
+        'more information, please see the discussion on issue #2266. (This'
+        ' warning should only appear once.)'),
+        DeprecationWarning)
+
+    charset_re = re.compile(r'<meta.*?charset=["\']*(.+?)["\'>]', flags=re.I)
+    pragma_re = re.compile(r'<meta.*?content=["\']*;?charset=(.+?)["\'>]', flags=re.I)
+    xml_re = re.compile(r'^<\?xml.*?encoding=["\']*(.+?)["\'>]')
+
+    return (charset_re.findall(content) +
+            pragma_re.findall(content) +
+            xml_re.findall(content))
+
+
+def _parse_content_type_header(header):
+    """Returns content type and parameters from given header
+
+    :param header: string
+    :return: tuple containing content type and dictionary of
+         parameters
+    """
+
+    tokens = header.split(';')
+    content_type, params = tokens[0].strip(), tokens[1:]
+    params_dict = {}
+    items_to_strip = "\"' "
+
+    for param in params:
+        param = param.strip()
+        if param:
+            key, value = param, True
+            index_of_equals = param.find("=")
+            if index_of_equals != -1:
+                key = param[:index_of_equals].strip(items_to_strip)
+                value = param[index_of_equals + 1:].strip(items_to_strip)
+            params_dict[key.lower()] = value
+    return content_type, params_dict
+
+
+def get_encoding_from_headers(headers):
+    """Returns encodings from given HTTP Header Dict.
+
+    :param headers: dictionary to extract encoding from.
+    :rtype: str
+    """
+
+    content_type = headers.get('content-type')
+
+    if not content_type:
+        return None
+
+    content_type, params = _parse_content_type_header(content_type)
+
+    if 'charset' in params:
+        return params['charset'].strip("'\"")
+
+    if 'text' in content_type:
+        return 'ISO-8859-1'
+
+
+def stream_decode_response_unicode(iterator, r):
+    """Stream decodes a iterator."""
+
+    if r.encoding is None:
+        for item in iterator:
+            yield item
+        return
+
+    decoder = codecs.getincrementaldecoder(r.encoding)(errors='replace')
+    for chunk in iterator:
+        rv = decoder.decode(chunk)
+        if rv:
+            yield rv
+    rv = decoder.decode(b'', final=True)
+    if rv:
+        yield rv
+
+
+def iter_slices(string, slice_length):
+    """Iterate over slices of a string."""
+    pos = 0
+    if slice_length is None or slice_length <= 0:
+        slice_length = len(string)
+    while pos < len(string):
+        yield string[pos:pos + slice_length]
+        pos += slice_length
+
+
+def get_unicode_from_response(r):
+    """Returns the requested content back in unicode.
+
+    :param r: Response object to get unicode content from.
+
+    Tried:
+
+    1. charset from content-type
+    2. fall back and replace all unicode characters
+
+    :rtype: str
+    """
+    warnings.warn((
+        'In requests 3.0, get_unicode_from_response will be removed. For '
+        'more information, please see the discussion on issue #2266. (This'
+        ' warning should only appear once.)'),
+        DeprecationWarning)
+
+    tried_encodings = []
+
+    # Try charset from content-type
+    encoding = get_encoding_from_headers(r.headers)
+
+    if encoding:
+        try:
+            return str(r.content, encoding)
+        except UnicodeError:
+            tried_encodings.append(encoding)
+
+    # Fall back:
+    try:
+        return str(r.content, encoding, errors='replace')
+    except TypeError:
+        return r.content
+
+
+# The unreserved URI characters (RFC 3986)
+UNRESERVED_SET = frozenset(
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" + "0123456789-._~")
+
+
+def unquote_unreserved(uri):
+    """Un-escape any percent-escape sequences in a URI that are unreserved
+    characters. This leaves all reserved, illegal and non-ASCII bytes encoded.
+
+    :rtype: str
+    """
+    parts = uri.split('%')
+    for i in range(1, len(parts)):
+        h = parts[i][0:2]
+        if len(h) == 2 and h.isalnum():
+            try:
+                c = chr(int(h, 16))
+            except ValueError:
+                raise InvalidURL("Invalid percent-escape sequence: '%s'" % h)
+
+            if c in UNRESERVED_SET:
+                parts[i] = c + parts[i][2:]
+            else:
+                parts[i] = '%' + parts[i]
+        else:
+            parts[i] = '%' + parts[i]
+    return ''.join(parts)
+
+
+def requote_uri(uri):
+    """Re-quote the given URI.
+
+    This function passes the given URI through an unquote/quote cycle to
+    ensure that it is fully and consistently quoted.
+
+    :rtype: str
+    """
+    safe_with_percent = "!#$%&'()*+,/:;=?@[]~"
+    safe_without_percent = "!#$&'()*+,/:;=?@[]~"
+    try:
+        # Unquote only the unreserved characters
+        # Then quote only illegal characters (do not quote reserved,
+        # unreserved, or '%')
+        return quote(unquote_unreserved(uri), safe=safe_with_percent)
+    except InvalidURL:
+        # We couldn't unquote the given URI, so let's try quoting it, but
+        # there may be unquoted '%'s in the URI. We need to make sure they're
+        # properly quoted so they do not cause issues elsewhere.
+        return quote(uri, safe=safe_without_percent)
+
+
+def address_in_network(ip, net):
+    """This function allows you to check if an IP belongs to a network subnet
+
+    Example: returns True if ip = 192.168.1.1 and net = 192.168.1.0/24
+             returns False if ip = 192.168.1.1 and net = 192.168.100.0/24
+
+    :rtype: bool
+    """
+    ipaddr = struct.unpack('=L', socket.inet_aton(ip))[0]
+    netaddr, bits = net.split('/')
+    netmask = struct.unpack('=L', socket.inet_aton(dotted_netmask(int(bits))))[0]
+    network = struct.unpack('=L', socket.inet_aton(netaddr))[0] & netmask
+    return (ipaddr & netmask) == (network & netmask)
+
+
+def dotted_netmask(mask):
+    """Converts mask from /xx format to xxx.xxx.xxx.xxx
+
+    Example: if mask is 24 function returns 255.255.255.0
+
+    :rtype: str
+    """
+    bits = 0xffffffff ^ (1 << 32 - mask) - 1
+    return socket.inet_ntoa(struct.pack('>I', bits))
+
+
+def is_ipv4_address(string_ip):
+    """
+    :rtype: bool
+    """
+    try:
+        socket.inet_aton(string_ip)
+    except socket.error:
+        return False
+    return True
+
+
+def is_valid_cidr(string_network):
+    """
+    Very simple check of the cidr format in no_proxy variable.
+
+    :rtype: bool
+    """
+    if string_network.count('/') == 1:
+        try:
+            mask = int(string_network.split('/')[1])
+        except ValueError:
+            return False
+
+        if mask < 1 or mask > 32:
+            return False
+
+        try:
+            socket.inet_aton(string_network.split('/')[0])
+        except socket.error:
+            return False
+    else:
+        return False
+    return True
+
+
+@contextlib.contextmanager
+def set_environ(env_name, value):
+    """Set the environment variable 'env_name' to 'value'
+
+    Save previous value, yield, and then restore the previous value stored in
+    the environment variable 'env_name'.
+
+    If 'value' is None, do nothing"""
+    value_changed = value is not None
+    if value_changed:
+        old_value = os.environ.get(env_name)
+        os.environ[env_name] = value
+    try:
+        yield
+    finally:
+        if value_changed:
+            if old_value is None:
+                del os.environ[env_name]
+            else:
+                os.environ[env_name] = old_value
+
+
+def should_bypass_proxies(url, no_proxy):
+    """
+    Returns whether we should bypass proxies or not.
+
+    :rtype: bool
+    """
+    # Prioritize lowercase environment variables over uppercase
+    # to keep a consistent behaviour with other http projects (curl, wget).
+    get_proxy = lambda k: os.environ.get(k) or os.environ.get(k.upper())
+
+    # First check whether no_proxy is defined. If it is, check that the URL
+    # we're getting isn't in the no_proxy list.
+    no_proxy_arg = no_proxy
+    if no_proxy is None:
+        no_proxy = get_proxy('no_proxy')
+    parsed = urlparse(url)
+
+    if parsed.hostname is None:
+        # URLs don't always have hostnames, e.g. file:/// urls.
+        return True
+
+    if no_proxy:
+        # We need to check whether we match here. We need to see if we match
+        # the end of the hostname, both with and without the port.
+        no_proxy = (
+            host for host in no_proxy.replace(' ', '').split(',') if host
+        )
+
+        if is_ipv4_address(parsed.hostname):
+            for proxy_ip in no_proxy:
+                if is_valid_cidr(proxy_ip):
+                    if address_in_network(parsed.hostname, proxy_ip):
+                        return True
+                elif parsed.hostname == proxy_ip:
+                    # If no_proxy ip was defined in plain IP notation instead of cidr notation &
+                    # matches the IP of the index
+                    return True
+        else:
+            host_with_port = parsed.hostname
+            if parsed.port:
+                host_with_port += ':{}'.format(parsed.port)
+
+            for host in no_proxy:
+                if parsed.hostname.endswith(host) or host_with_port.endswith(host):
+                    # The URL does match something in no_proxy, so we don't want
+                    # to apply the proxies on this URL.
+                    return True
+
+    with set_environ('no_proxy', no_proxy_arg):
+        # parsed.hostname can be `None` in cases such as a file URI.
+        try:
+            bypass = proxy_bypass(parsed.hostname)
+        except (TypeError, socket.gaierror):
+            bypass = False
+
+    if bypass:
+        return True
+
+    return False
+
+
+def get_environ_proxies(url, no_proxy=None):
+    """
+    Return a dict of environment proxies.
+
+    :rtype: dict
+    """
+    if should_bypass_proxies(url, no_proxy=no_proxy):
+        return {}
+    else:
+        return getproxies()
+
+
+def select_proxy(url, proxies):
+    """Select a proxy for the url, if applicable.
+
+    :param url: The url being for the request
+    :param proxies: A dictionary of schemes or schemes and hosts to proxy URLs
+    """
+    proxies = proxies or {}
+    urlparts = urlparse(url)
+    if urlparts.hostname is None:
+        return proxies.get(urlparts.scheme, proxies.get('all'))
+
+    proxy_keys = [
+        urlparts.scheme + '://' + urlparts.hostname,
+        urlparts.scheme,
+        'all://' + urlparts.hostname,
+        'all',
+    ]
+    proxy = None
+    for proxy_key in proxy_keys:
+        if proxy_key in proxies:
+            proxy = proxies[proxy_key]
+            break
+
+    return proxy
+
+
+def default_user_agent(name="python-requests"):
+    """
+    Return a string representing the default user agent.
+
+    :rtype: str
+    """
+    return '%s/%s' % (name, __version__)
+
+
+def default_headers():
+    """
+    :rtype: requests.structures.CaseInsensitiveDict
+    """
+    return CaseInsensitiveDict({
+        'User-Agent': default_user_agent(),
+        'Accept-Encoding': ', '.join(('gzip', 'deflate')),
+        'Accept': '*/*',
+        'Connection': 'keep-alive',
+    })
+
+
+def parse_header_links(value):
+    """Return a list of parsed link headers proxies.
+
+    i.e. Link: <http:/.../front.jpeg>; rel=front; type="image/jpeg",<http://.../back.jpeg>; rel=back;type="image/jpeg"
+
+    :rtype: list
+    """
+
+    links = []
+
+    replace_chars = ' \'"'
+
+    value = value.strip(replace_chars)
+    if not value:
+        return links
+
+    for val in re.split(', *<', value):
+        try:
+            url, params = val.split(';', 1)
+        except ValueError:
+            url, params = val, ''
+
+        link = {'url': url.strip('<> \'"')}
+
+        for param in params.split(';'):
+            try:
+                key, value = param.split('=')
+            except ValueError:
+                break
+
+            link[key.strip(replace_chars)] = value.strip(replace_chars)
+
+        links.append(link)
+
+    return links
+
+
+# Null bytes; no need to recreate these on each call to guess_json_utf
+_null = '\x00'.encode('ascii')  # encoding to ASCII for Python 3
+_null2 = _null * 2
+_null3 = _null * 3
+
+
+def guess_json_utf(data):
+    """
+    :rtype: str
+    """
+    # JSON always starts with two ASCII characters, so detection is as
+    # easy as counting the nulls and from their location and count
+    # determine the encoding. Also detect a BOM, if present.
+    sample = data[:4]
+    if sample in (codecs.BOM_UTF32_LE, codecs.BOM_UTF32_BE):
+        return 'utf-32'     # BOM included
+    if sample[:3] == codecs.BOM_UTF8:
+        return 'utf-8-sig'  # BOM included, MS style (discouraged)
+    if sample[:2] in (codecs.BOM_UTF16_LE, codecs.BOM_UTF16_BE):
+        return 'utf-16'     # BOM included
+    nullcount = sample.count(_null)
+    if nullcount == 0:
+        return 'utf-8'
+    if nullcount == 2:
+        if sample[::2] == _null2:   # 1st and 3rd are null
+            return 'utf-16-be'
+        if sample[1::2] == _null2:  # 2nd and 4th are null
+            return 'utf-16-le'
+        # Did not detect 2 valid UTF-16 ascii-range characters
+    if nullcount == 3:
+        if sample[:3] == _null3:
+            return 'utf-32-be'
+        if sample[1:] == _null3:
+            return 'utf-32-le'
+        # Did not detect a valid UTF-32 ascii-range character
+    return None
+
+
+def prepend_scheme_if_needed(url, new_scheme):
+    """Given a URL that may or may not have a scheme, prepend the given scheme.
+    Does not replace a present scheme with the one provided as an argument.
+
+    :rtype: str
+    """
+    scheme, netloc, path, params, query, fragment = urlparse(url, new_scheme)
+
+    # urlparse is a finicky beast, and sometimes decides that there isn't a
+    # netloc present. Assume that it's being over-cautious, and switch netloc
+    # and path if urlparse decided there was no netloc.
+    if not netloc:
+        netloc, path = path, netloc
+
+    return urlunparse((scheme, netloc, path, params, query, fragment))
+
+
+def get_auth_from_url(url):
+    """Given a url with authentication components, extract them into a tuple of
+    username,password.
+
+    :rtype: (str,str)
+    """
+    parsed = urlparse(url)
+
+    try:
+        auth = (unquote(parsed.username), unquote(parsed.password))
+    except (AttributeError, TypeError):
+        auth = ('', '')
+
+    return auth
+
+
+# Moved outside of function to avoid recompile every call
+_CLEAN_HEADER_REGEX_BYTE = re.compile(b'^\\S[^\\r\\n]*$|^$')
+_CLEAN_HEADER_REGEX_STR = re.compile(r'^\S[^\r\n]*$|^$')
+
+
+def check_header_validity(header):
+    """Verifies that header value is a string which doesn't contain
+    leading whitespace or return characters. This prevents unintended
+    header injection.
+
+    :param header: tuple, in the format (name, value).
+    """
+    name, value = header
+
+    if isinstance(value, bytes):
+        pat = _CLEAN_HEADER_REGEX_BYTE
+    else:
+        pat = _CLEAN_HEADER_REGEX_STR
+    try:
+        if not pat.match(value):
+            raise InvalidHeader("Invalid return character or leading space in header: %s" % name)
+    except TypeError:
+        raise InvalidHeader("Value for header {%s: %s} must be of type str or "
+                            "bytes, not %s" % (name, value, type(value)))
+
+
+def urldefragauth(url):
+    """
+    Given a url remove the fragment and the authentication part.
+
+    :rtype: str
+    """
+    scheme, netloc, path, params, query, fragment = urlparse(url)
+
+    # see func:`prepend_scheme_if_needed`
+    if not netloc:
+        netloc, path = path, netloc
+
+    netloc = netloc.rsplit('@', 1)[-1]
+
+    return urlunparse((scheme, netloc, path, params, query, ''))
+
+
+def rewind_body(prepared_request):
+    """Move file pointer back to its recorded starting position
+    so it can be read again on redirect.
+    """
+    body_seek = getattr(prepared_request.body, 'seek', None)
+    if body_seek is not None and isinstance(prepared_request._body_position, integer_types):
+        try:
+            body_seek(prepared_request._body_position)
+        except (IOError, OSError):
+            raise UnrewindableBodyError("An error occurred when rewinding request "
+                                        "body for redirect.")
+    else:
+        raise UnrewindableBodyError("Unable to rewind request body for redirect.")