Created starter files for the project.

venv/Lib/site-packages/pip/_internal/operations/check.py

@@ -0,0 +1,158 @@
+"""Validation of dependencies of packages
+"""
+
+import logging
+from collections import namedtuple
+
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import RequirementParseError
+
+from pip._internal.distributions import (
+    make_distribution_for_install_requirement,
+)
+from pip._internal.utils.misc import get_installed_distributions
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+logger = logging.getLogger(__name__)
+
+if MYPY_CHECK_RUNNING:
+    from pip._internal.req.req_install import InstallRequirement
+    from typing import (
+        Any, Callable, Dict, Optional, Set, Tuple, List
+    )
+
+    # Shorthands
+    PackageSet = Dict[str, 'PackageDetails']
+    Missing = Tuple[str, Any]
+    Conflicting = Tuple[str, str, Any]
+
+    MissingDict = Dict[str, List[Missing]]
+    ConflictingDict = Dict[str, List[Conflicting]]
+    CheckResult = Tuple[MissingDict, ConflictingDict]
+    ConflictDetails = Tuple[PackageSet, CheckResult]
+
+PackageDetails = namedtuple('PackageDetails', ['version', 'requires'])
+
+
+def create_package_set_from_installed(**kwargs):
+    # type: (**Any) -> Tuple[PackageSet, bool]
+    """Converts a list of distributions into a PackageSet.
+    """
+    # Default to using all packages installed on the system
+    if kwargs == {}:
+        kwargs = {"local_only": False, "skip": ()}
+
+    package_set = {}
+    problems = False
+    for dist in get_installed_distributions(**kwargs):
+        name = canonicalize_name(dist.project_name)
+        try:
+            package_set[name] = PackageDetails(dist.version, dist.requires())
+        except RequirementParseError as e:
+            # Don't crash on broken metadata
+            logger.warning("Error parsing requirements for %s: %s", name, e)
+            problems = True
+    return package_set, problems
+
+
+def check_package_set(package_set, should_ignore=None):
+    # type: (PackageSet, Optional[Callable[[str], bool]]) -> CheckResult
+    """Check if a package set is consistent
+
+    If should_ignore is passed, it should be a callable that takes a
+    package name and returns a boolean.
+    """
+
+    missing = {}
+    conflicting = {}
+
+    for package_name in package_set:
+        # Info about dependencies of package_name
+        missing_deps = set()  # type: Set[Missing]
+        conflicting_deps = set()  # type: Set[Conflicting]
+
+        if should_ignore and should_ignore(package_name):
+            continue
+
+        for req in package_set[package_name].requires:
+            name = canonicalize_name(req.project_name)  # type: str
+
+            # Check if it's missing
+            if name not in package_set:
+                missed = True
+                if req.marker is not None:
+                    missed = req.marker.evaluate()
+                if missed:
+                    missing_deps.add((name, req))
+                continue
+
+            # Check if there's a conflict
+            version = package_set[name].version  # type: str
+            if not req.specifier.contains(version, prereleases=True):
+                conflicting_deps.add((name, version, req))
+
+        if missing_deps:
+            missing[package_name] = sorted(missing_deps, key=str)
+        if conflicting_deps:
+            conflicting[package_name] = sorted(conflicting_deps, key=str)
+
+    return missing, conflicting
+
+
+def check_install_conflicts(to_install):
+    # type: (List[InstallRequirement]) -> ConflictDetails
+    """For checking if the dependency graph would be consistent after \
+    installing given requirements
+    """
+    # Start from the current state
+    package_set, _ = create_package_set_from_installed()
+    # Install packages
+    would_be_installed = _simulate_installation_of(to_install, package_set)
+
+    # Only warn about directly-dependent packages; create a whitelist of them
+    whitelist = _create_whitelist(would_be_installed, package_set)
+
+    return (
+        package_set,
+        check_package_set(
+            package_set, should_ignore=lambda name: name not in whitelist
+        )
+    )
+
+
+def _simulate_installation_of(to_install, package_set):
+    # type: (List[InstallRequirement], PackageSet) -> Set[str]
+    """Computes the version of packages after installing to_install.
+    """
+
+    # Keep track of packages that were installed
+    installed = set()
+
+    # Modify it as installing requirement_set would (assuming no errors)
+    for inst_req in to_install:
+        abstract_dist = make_distribution_for_install_requirement(inst_req)
+        dist = abstract_dist.get_pkg_resources_distribution()
+
+        assert dist is not None
+        name = canonicalize_name(dist.key)
+        package_set[name] = PackageDetails(dist.version, dist.requires())
+
+        installed.add(name)
+
+    return installed
+
+
+def _create_whitelist(would_be_installed, package_set):
+    # type: (Set[str], PackageSet) -> Set[str]
+    packages_affected = set(would_be_installed)
+
+    for package_name in package_set:
+        if package_name in packages_affected:
+            continue
+
+        for req in package_set[package_name].requires:
+            if canonicalize_name(req.name) in packages_affected:
+                packages_affected.add(package_name)
+                break
+
+    return packages_affected