Uploaded Test files

venv/Lib/site-packages/async_generator/__init__.py

@@ -0,0 +1,23 @@
+from ._version import __version__
+from ._impl import (
+    async_generator,
+    yield_,
+    yield_from_,
+    isasyncgen,
+    isasyncgenfunction,
+    get_asyncgen_hooks,
+    set_asyncgen_hooks,
+)
+from ._util import aclosing, asynccontextmanager
+
+__all__ = [
+    "async_generator",
+    "yield_",
+    "yield_from_",
+    "aclosing",
+    "isasyncgen",
+    "isasyncgenfunction",
+    "asynccontextmanager",
+    "get_asyncgen_hooks",
+    "set_asyncgen_hooks",
+]

venv/Lib/site-packages/async_generator/_impl.py

@@ -0,0 +1,455 @@
+import sys
+from functools import wraps
+from types import coroutine
+import inspect
+from inspect import (
+    getcoroutinestate, CORO_CREATED, CORO_CLOSED, CORO_SUSPENDED
+)
+import collections.abc
+
+
+class YieldWrapper:
+    def __init__(self, payload):
+        self.payload = payload
+
+
+def _wrap(value):
+    return YieldWrapper(value)
+
+
+def _is_wrapped(box):
+    return isinstance(box, YieldWrapper)
+
+
+def _unwrap(box):
+    return box.payload
+
+
+# This is the magic code that lets you use yield_ and yield_from_ with native
+# generators.
+#
+# The old version worked great on Linux and MacOS, but not on Windows, because
+# it depended on _PyAsyncGenValueWrapperNew. The new version segfaults
+# everywhere, and I'm not sure why -- probably my lack of understanding
+# of ctypes and refcounts.
+#
+# There are also some commented out tests that should be re-enabled if this is
+# fixed:
+#
+# if sys.version_info >= (3, 6):
+#     # Use the same box type that the interpreter uses internally. This allows
+#     # yield_ and (more importantly!) yield_from_ to work in built-in
+#     # generators.
+#     import ctypes  # mua ha ha.
+#
+#     # We used to call _PyAsyncGenValueWrapperNew to create and set up new
+#     # wrapper objects, but that symbol isn't available on Windows:
+#     #
+#     #   https://github.com/python-trio/async_generator/issues/5
+#     #
+#     # Fortunately, the type object is available, but it means we have to do
+#     # this the hard way.
+#
+#     # We don't actually need to access this, but we need to make a ctypes
+#     # structure so we can call addressof.
+#     class _ctypes_PyTypeObject(ctypes.Structure):
+#         pass
+#     _PyAsyncGenWrappedValue_Type_ptr = ctypes.addressof(
+#         _ctypes_PyTypeObject.in_dll(
+#             ctypes.pythonapi, "_PyAsyncGenWrappedValue_Type"))
+#     _PyObject_GC_New = ctypes.pythonapi._PyObject_GC_New
+#     _PyObject_GC_New.restype = ctypes.py_object
+#     _PyObject_GC_New.argtypes = (ctypes.c_void_p,)
+#
+#     _Py_IncRef = ctypes.pythonapi.Py_IncRef
+#     _Py_IncRef.restype = None
+#     _Py_IncRef.argtypes = (ctypes.py_object,)
+#
+#     class _ctypes_PyAsyncGenWrappedValue(ctypes.Structure):
+#         _fields_ = [
+#             ('PyObject_HEAD', ctypes.c_byte * object().__sizeof__()),
+#             ('agw_val', ctypes.py_object),
+#         ]
+#     def _wrap(value):
+#         box = _PyObject_GC_New(_PyAsyncGenWrappedValue_Type_ptr)
+#         raw = ctypes.cast(ctypes.c_void_p(id(box)),
+#                           ctypes.POINTER(_ctypes_PyAsyncGenWrappedValue))
+#         raw.contents.agw_val = value
+#         _Py_IncRef(value)
+#         return box
+#
+#     def _unwrap(box):
+#         assert _is_wrapped(box)
+#         raw = ctypes.cast(ctypes.c_void_p(id(box)),
+#                           ctypes.POINTER(_ctypes_PyAsyncGenWrappedValue))
+#         value = raw.contents.agw_val
+#         _Py_IncRef(value)
+#         return value
+#
+#     _PyAsyncGenWrappedValue_Type = type(_wrap(1))
+#     def _is_wrapped(box):
+#         return isinstance(box, _PyAsyncGenWrappedValue_Type)
+
+
+# The magic @coroutine decorator is how you write the bottom level of
+# coroutine stacks -- 'async def' can only use 'await' = yield from; but
+# eventually we must bottom out in a @coroutine that calls plain 'yield'.
+@coroutine
+def _yield_(value):
+    return (yield _wrap(value))
+
+
+# But we wrap the bare @coroutine version in an async def, because async def
+# has the magic feature that users can get warnings messages if they forget to
+# use 'await'.
+async def yield_(value=None):
+    return await _yield_(value)
+
+
+async def yield_from_(delegate):
+    # Transcribed with adaptations from:
+    #
+    #   https://www.python.org/dev/peps/pep-0380/#formal-semantics
+    #
+    # This takes advantage of a sneaky trick: if an @async_generator-wrapped
+    # function calls another async function (like yield_from_), and that
+    # second async function calls yield_, then because of the hack we use to
+    # implement yield_, the yield_ will actually propagate through yield_from_
+    # back to the @async_generator wrapper. So even though we're a regular
+    # function, we can directly yield values out of the calling async
+    # generator.
+    def unpack_StopAsyncIteration(e):
+        if e.args:
+            return e.args[0]
+        else:
+            return None
+
+    _i = type(delegate).__aiter__(delegate)
+    if hasattr(_i, "__await__"):
+        _i = await _i
+    try:
+        _y = await type(_i).__anext__(_i)
+    except StopAsyncIteration as _e:
+        _r = unpack_StopAsyncIteration(_e)
+    else:
+        while 1:
+            try:
+                _s = await yield_(_y)
+            except GeneratorExit as _e:
+                try:
+                    _m = _i.aclose
+                except AttributeError:
+                    pass
+                else:
+                    await _m()
+                raise _e
+            except BaseException as _e:
+                _x = sys.exc_info()
+                try:
+                    _m = _i.athrow
+                except AttributeError:
+                    raise _e
+                else:
+                    try:
+                        _y = await _m(*_x)
+                    except StopAsyncIteration as _e:
+                        _r = unpack_StopAsyncIteration(_e)
+                        break
+            else:
+                try:
+                    if _s is None:
+                        _y = await type(_i).__anext__(_i)
+                    else:
+                        _y = await _i.asend(_s)
+                except StopAsyncIteration as _e:
+                    _r = unpack_StopAsyncIteration(_e)
+                    break
+    return _r
+
+
+# This is the awaitable / iterator that implements asynciter.__anext__() and
+# friends.
+#
+# Note: we can be sloppy about the distinction between
+#
+#   type(self._it).__next__(self._it)
+#
+# and
+#
+#   self._it.__next__()
+#
+# because we happen to know that self._it is not a general iterator object,
+# but specifically a coroutine iterator object where these are equivalent.
+class ANextIter:
+    def __init__(self, it, first_fn, *first_args):
+        self._it = it
+        self._first_fn = first_fn
+        self._first_args = first_args
+
+    def __await__(self):
+        return self
+
+    def __next__(self):
+        if self._first_fn is not None:
+            first_fn = self._first_fn
+            first_args = self._first_args
+            self._first_fn = self._first_args = None
+            return self._invoke(first_fn, *first_args)
+        else:
+            return self._invoke(self._it.__next__)
+
+    def send(self, value):
+        return self._invoke(self._it.send, value)
+
+    def throw(self, type, value=None, traceback=None):
+        return self._invoke(self._it.throw, type, value, traceback)
+
+    def _invoke(self, fn, *args):
+        try:
+            result = fn(*args)
+        except StopIteration as e:
+            # The underlying generator returned, so we should signal the end
+            # of iteration.
+            raise StopAsyncIteration(e.value)
+        except StopAsyncIteration as e:
+            # PEP 479 says: if a generator raises Stop(Async)Iteration, then
+            # it should be wrapped into a RuntimeError. Python automatically
+            # enforces this for StopIteration; for StopAsyncIteration we need
+            # to it ourselves.
+            raise RuntimeError(
+                "async_generator raise StopAsyncIteration"
+            ) from e
+        if _is_wrapped(result):
+            raise StopIteration(_unwrap(result))
+        else:
+            return result
+
+
+UNSPECIFIED = object()
+try:
+    from sys import get_asyncgen_hooks, set_asyncgen_hooks
+
+except ImportError:
+    import threading
+
+    asyncgen_hooks = collections.namedtuple(
+        "asyncgen_hooks", ("firstiter", "finalizer")
+    )
+
+    class _hooks_storage(threading.local):
+        def __init__(self):
+            self.firstiter = None
+            self.finalizer = None
+
+    _hooks = _hooks_storage()
+
+    def get_asyncgen_hooks():
+        return asyncgen_hooks(
+            firstiter=_hooks.firstiter, finalizer=_hooks.finalizer
+        )
+
+    def set_asyncgen_hooks(firstiter=UNSPECIFIED, finalizer=UNSPECIFIED):
+        if firstiter is not UNSPECIFIED:
+            if firstiter is None or callable(firstiter):
+                _hooks.firstiter = firstiter
+            else:
+                raise TypeError(
+                    "callable firstiter expected, got {}".format(
+                        type(firstiter).__name__
+                    )
+                )
+
+        if finalizer is not UNSPECIFIED:
+            if finalizer is None or callable(finalizer):
+                _hooks.finalizer = finalizer
+            else:
+                raise TypeError(
+                    "callable finalizer expected, got {}".format(
+                        type(finalizer).__name__
+                    )
+                )
+
+
+class AsyncGenerator:
+    # https://bitbucket.org/pypy/pypy/issues/2786:
+    # PyPy implements 'await' in a way that requires the frame object
+    # used to execute a coroutine to keep a weakref to that coroutine.
+    # During a GC pass, weakrefs to all doomed objects are broken
+    # before any of the doomed objects' finalizers are invoked.
+    # If an AsyncGenerator is unreachable, its _coroutine probably
+    # is too, and the weakref from ag._coroutine.cr_frame to
+    # ag._coroutine will be broken before ag.__del__ can do its
+    # one-turn close attempt or can schedule a full aclose() using
+    # the registered finalization hook. It doesn't look like the
+    # underlying issue is likely to be fully fixed anytime soon,
+    # so we work around it by preventing an AsyncGenerator and
+    # its _coroutine from being considered newly unreachable at
+    # the same time if the AsyncGenerator's finalizer might want
+    # to iterate the coroutine some more.
+    _pypy_issue2786_workaround = set()
+
+    def __init__(self, coroutine):
+        self._coroutine = coroutine
+        self._it = coroutine.__await__()
+        self.ag_running = False
+        self._finalizer = None
+        self._closed = False
+        self._hooks_inited = False
+
+    # On python 3.5.0 and 3.5.1, __aiter__ must be awaitable.
+    # Starting in 3.5.2, it should not be awaitable, and if it is, then it
+    #   raises a PendingDeprecationWarning.
+    # See:
+    #   https://www.python.org/dev/peps/pep-0492/#api-design-and-implementation-revisions
+    #   https://docs.python.org/3/reference/datamodel.html#async-iterators
+    #   https://bugs.python.org/issue27243
+    if sys.version_info < (3, 5, 2):
+
+        async def __aiter__(self):
+            return self
+    else:
+
+        def __aiter__(self):
+            return self
+
+    ################################################################
+    # Introspection attributes
+    ################################################################
+
+    @property
+    def ag_code(self):
+        return self._coroutine.cr_code
+
+    @property
+    def ag_frame(self):
+        return self._coroutine.cr_frame
+
+    ################################################################
+    # Core functionality
+    ################################################################
+
+    # These need to return awaitables, rather than being async functions,
+    # to match the native behavior where the firstiter hook is called
+    # immediately on asend()/etc, even if the coroutine that asend()
+    # produces isn't awaited for a bit.
+
+    def __anext__(self):
+        return self._do_it(self._it.__next__)
+
+    def asend(self, value):
+        return self._do_it(self._it.send, value)
+
+    def athrow(self, type, value=None, traceback=None):
+        return self._do_it(self._it.throw, type, value, traceback)
+
+    def _do_it(self, start_fn, *args):
+        if not self._hooks_inited:
+            self._hooks_inited = True
+            (firstiter, self._finalizer) = get_asyncgen_hooks()
+            if firstiter is not None:
+                firstiter(self)
+            if sys.implementation.name == "pypy":
+                self._pypy_issue2786_workaround.add(self._coroutine)
+
+        # On CPython 3.5.2 (but not 3.5.0), coroutines get cranky if you try
+        # to iterate them after they're exhausted. Generators OTOH just raise
+        # StopIteration. We want to convert the one into the other, so we need
+        # to avoid iterating stopped coroutines.
+        if getcoroutinestate(self._coroutine) is CORO_CLOSED:
+            raise StopAsyncIteration()
+
+        async def step():
+            if self.ag_running:
+                raise ValueError("async generator already executing")
+            try:
+                self.ag_running = True
+                return await ANextIter(self._it, start_fn, *args)
+            except StopAsyncIteration:
+                self._pypy_issue2786_workaround.discard(self._coroutine)
+                raise
+            finally:
+                self.ag_running = False
+
+        return step()
+
+    ################################################################
+    # Cleanup
+    ################################################################
+
+    async def aclose(self):
+        state = getcoroutinestate(self._coroutine)
+        if state is CORO_CLOSED or self._closed:
+            return
+        # Make sure that even if we raise "async_generator ignored
+        # GeneratorExit", and thus fail to exhaust the coroutine,
+        # __del__ doesn't complain again.
+        self._closed = True
+        if state is CORO_CREATED:
+            # Make sure that aclose() on an unstarted generator returns
+            # successfully and prevents future iteration.
+            self._it.close()
+            return
+        try:
+            await self.athrow(GeneratorExit)
+        except (GeneratorExit, StopAsyncIteration):
+            self._pypy_issue2786_workaround.discard(self._coroutine)
+        else:
+            raise RuntimeError("async_generator ignored GeneratorExit")
+
+    def __del__(self):
+        self._pypy_issue2786_workaround.discard(self._coroutine)
+        if getcoroutinestate(self._coroutine) is CORO_CREATED:
+            # Never started, nothing to clean up, just suppress the "coroutine
+            # never awaited" message.
+            self._coroutine.close()
+        if getcoroutinestate(self._coroutine
+                             ) is CORO_SUSPENDED and not self._closed:
+            if self._finalizer is not None:
+                self._finalizer(self)
+            else:
+                # Mimic the behavior of native generators on GC with no finalizer:
+                # throw in GeneratorExit, run for one turn, and complain if it didn't
+                # finish.
+                thrower = self.athrow(GeneratorExit)
+                try:
+                    thrower.send(None)
+                except (GeneratorExit, StopAsyncIteration):
+                    pass
+                except StopIteration:
+                    raise RuntimeError("async_generator ignored GeneratorExit")
+                else:
+                    raise RuntimeError(
+                        "async_generator {!r} awaited during finalization; install "
+                        "a finalization hook to support this, or wrap it in "
+                        "'async with aclosing(...):'"
+                        .format(self.ag_code.co_name)
+                    )
+                finally:
+                    thrower.close()
+
+
+if hasattr(collections.abc, "AsyncGenerator"):
+    collections.abc.AsyncGenerator.register(AsyncGenerator)
+
+
+def async_generator(coroutine_maker):
+    @wraps(coroutine_maker)
+    def async_generator_maker(*args, **kwargs):
+        return AsyncGenerator(coroutine_maker(*args, **kwargs))
+
+    async_generator_maker._async_gen_function = id(async_generator_maker)
+    return async_generator_maker
+
+
+def isasyncgen(obj):
+    if hasattr(inspect, "isasyncgen"):
+        if inspect.isasyncgen(obj):
+            return True
+    return isinstance(obj, AsyncGenerator)
+
+
+def isasyncgenfunction(obj):
+    if hasattr(inspect, "isasyncgenfunction"):
+        if inspect.isasyncgenfunction(obj):
+            return True
+    return getattr(obj, "_async_gen_function", -1) == id(obj)

venv/Lib/site-packages/async_generator/_tests/conftest.py

@@ -0,0 +1,36 @@
+import pytest
+from functools import wraps, partial
+import inspect
+import types
+
+
+@types.coroutine
+def mock_sleep():
+    yield "mock_sleep"
+
+
+# Wrap any 'async def' tests so that they get automatically iterated.
+# We used to use pytest-asyncio as a convenient way to do this, but nowadays
+# pytest-asyncio uses us! In addition to it being generally bad for our test
+# infrastructure to depend on the code-under-test, this totally messes up
+# coverage info because depending on pytest's plugin load order, we might get
+# imported before pytest-cov can be loaded and start gathering coverage.
+@pytest.hookimpl(tryfirst=True)
+def pytest_pyfunc_call(pyfuncitem):
+    if inspect.iscoroutinefunction(pyfuncitem.obj):
+        fn = pyfuncitem.obj
+
+        @wraps(fn)
+        def wrapper(**kwargs):
+            coro = fn(**kwargs)
+            try:
+                while True:
+                    value = coro.send(None)
+                    if value != "mock_sleep":  # pragma: no cover
+                        raise RuntimeError(
+                            "coroutine runner confused: {!r}".format(value)
+                        )
+            except StopIteration:
+                pass
+
+        pyfuncitem.obj = wrapper

venv/Lib/site-packages/async_generator/_tests/test_util.py

@@ -0,0 +1,227 @@
+import pytest
+
+from .. import aclosing, async_generator, yield_, asynccontextmanager
+
+
+@async_generator
+async def async_range(count, closed_slot):
+    try:
+        for i in range(count):  # pragma: no branch
+            await yield_(i)
+    except GeneratorExit:
+        closed_slot[0] = True
+
+
+async def test_aclosing():
+    closed_slot = [False]
+    async with aclosing(async_range(10, closed_slot)) as gen:
+        it = iter(range(10))
+        async for item in gen:  # pragma: no branch
+            assert item == next(it)
+            if item == 4:
+                break
+    assert closed_slot[0]
+
+    closed_slot = [False]
+    try:
+        async with aclosing(async_range(10, closed_slot)) as gen:
+            it = iter(range(10))
+            async for item in gen:  # pragma: no branch
+                assert item == next(it)
+                if item == 4:
+                    raise ValueError()
+    except ValueError:
+        pass
+    assert closed_slot[0]
+
+
+async def test_contextmanager_do_not_unchain_non_stopiteration_exceptions():
+    @asynccontextmanager
+    @async_generator
+    async def manager_issue29692():
+        try:
+            await yield_()
+        except Exception as exc:
+            raise RuntimeError('issue29692:Chained') from exc
+
+    with pytest.raises(RuntimeError) as excinfo:
+        async with manager_issue29692():
+            raise ZeroDivisionError
+    assert excinfo.value.args[0] == 'issue29692:Chained'
+    assert isinstance(excinfo.value.__cause__, ZeroDivisionError)
+
+    # This is a little funky because of implementation details in
+    # async_generator It can all go away once we stop supporting Python3.5
+    with pytest.raises(RuntimeError) as excinfo:
+        async with manager_issue29692():
+            exc = StopIteration('issue29692:Unchained')
+            raise exc
+    assert excinfo.value.args[0] == 'issue29692:Chained'
+    cause = excinfo.value.__cause__
+    assert cause.args[0] == 'generator raised StopIteration'
+    assert cause.__cause__ is exc
+
+    with pytest.raises(StopAsyncIteration) as excinfo:
+        async with manager_issue29692():
+            raise StopAsyncIteration('issue29692:Unchained')
+    assert excinfo.value.args[0] == 'issue29692:Unchained'
+    assert excinfo.value.__cause__ is None
+
+    @asynccontextmanager
+    @async_generator
+    async def noop_async_context_manager():
+        await yield_()
+
+    with pytest.raises(StopIteration):
+        async with noop_async_context_manager():
+            raise StopIteration
+
+
+# Native async generators are only available from Python 3.6 and onwards
+nativeasyncgenerators = True
+try:
+    exec(
+        """
+@asynccontextmanager
+async def manager_issue29692_2():
+    try:
+        yield
+    except Exception as exc:
+        raise RuntimeError('issue29692:Chained') from exc
+"""
+    )
+except SyntaxError:
+    nativeasyncgenerators = False
+
+
+@pytest.mark.skipif(
+    not nativeasyncgenerators,
+    reason="Python < 3.6 doesn't have native async generators"
+)
+async def test_native_contextmanager_do_not_unchain_non_stopiteration_exceptions(
+):
+
+    with pytest.raises(RuntimeError) as excinfo:
+        async with manager_issue29692_2():
+            raise ZeroDivisionError
+    assert excinfo.value.args[0] == 'issue29692:Chained'
+    assert isinstance(excinfo.value.__cause__, ZeroDivisionError)
+
+    for cls in [StopIteration, StopAsyncIteration]:
+        with pytest.raises(cls) as excinfo:
+            async with manager_issue29692_2():
+                raise cls('issue29692:Unchained')
+        assert excinfo.value.args[0] == 'issue29692:Unchained'
+        assert excinfo.value.__cause__ is None
+
+
+async def test_asynccontextmanager_exception_passthrough():
+    # This was the cause of annoying coverage flapping, see gh-140
+    @asynccontextmanager
+    @async_generator
+    async def noop_async_context_manager():
+        await yield_()
+
+    for exc_type in [StopAsyncIteration, RuntimeError, ValueError]:
+        with pytest.raises(exc_type):
+            async with noop_async_context_manager():
+                raise exc_type
+
+    # And let's also check a boring nothing pass-through while we're at it
+    async with noop_async_context_manager():
+        pass
+
+
+async def test_asynccontextmanager_catches_exception():
+    @asynccontextmanager
+    @async_generator
+    async def catch_it():
+        with pytest.raises(ValueError):
+            await yield_()
+
+    async with catch_it():
+        raise ValueError
+
+
+async def test_asynccontextmanager_different_exception():
+    @asynccontextmanager
+    @async_generator
+    async def switch_it():
+        try:
+            await yield_()
+        except KeyError:
+            raise ValueError
+
+    with pytest.raises(ValueError):
+        async with switch_it():
+            raise KeyError
+
+
+async def test_asynccontextmanager_nice_message_on_sync_enter():
+    @asynccontextmanager
+    @async_generator
+    async def xxx():  # pragma: no cover
+        await yield_()
+
+    cm = xxx()
+
+    with pytest.raises(RuntimeError) as excinfo:
+        with cm:
+            pass  # pragma: no cover
+
+    assert "async with" in str(excinfo.value)
+
+    async with cm:
+        pass
+
+
+async def test_asynccontextmanager_no_yield():
+    @asynccontextmanager
+    @async_generator
+    async def yeehaw():
+        pass
+
+    with pytest.raises(RuntimeError) as excinfo:
+        async with yeehaw():
+            assert False  # pragma: no cover
+
+    assert "didn't yield" in str(excinfo.value)
+
+
+async def test_asynccontextmanager_too_many_yields():
+    closed_count = 0
+
+    @asynccontextmanager
+    @async_generator
+    async def doubleyield():
+        try:
+            await yield_()
+        except Exception:
+            pass
+        try:
+            await yield_()
+        finally:
+            nonlocal closed_count
+            closed_count += 1
+
+    with pytest.raises(RuntimeError) as excinfo:
+        async with doubleyield():
+            pass
+
+    assert "didn't stop" in str(excinfo.value)
+    assert closed_count == 1
+
+    with pytest.raises(RuntimeError) as excinfo:
+        async with doubleyield():
+            raise ValueError
+
+    assert "didn't stop after athrow" in str(excinfo.value)
+    assert closed_count == 2
+
+
+async def test_asynccontextmanager_requires_asyncgenfunction():
+    with pytest.raises(TypeError):
+
+        @asynccontextmanager
+        def syncgen():  # pragma: no cover
+            yield

venv/Lib/site-packages/async_generator/_util.py

@@ -0,0 +1,110 @@
+import sys
+from functools import wraps
+from ._impl import isasyncgenfunction
+
+
+class aclosing:
+    def __init__(self, aiter):
+        self._aiter = aiter
+
+    async def __aenter__(self):
+        return self._aiter
+
+    async def __aexit__(self, *args):
+        await self._aiter.aclose()
+
+
+# Very much derived from the one in contextlib, by copy/pasting and then
+# asyncifying everything. (Also I dropped the obscure support for using
+# context managers as function decorators. It could be re-added; I just
+# couldn't be bothered.)
+# So this is a derivative work licensed under the PSF License, which requires
+# the following notice:
+#
+# Copyright © 2001-2017 Python Software Foundation; All Rights Reserved
+class _AsyncGeneratorContextManager:
+    def __init__(self, func, args, kwds):
+        self._func_name = func.__name__
+        self._agen = func(*args, **kwds).__aiter__()
+
+    async def __aenter__(self):
+        if sys.version_info < (3, 5, 2):
+            self._agen = await self._agen
+        try:
+            return await self._agen.asend(None)
+        except StopAsyncIteration:
+            raise RuntimeError("async generator didn't yield") from None
+
+    async def __aexit__(self, type, value, traceback):
+        async with aclosing(self._agen):
+            if type is None:
+                try:
+                    await self._agen.asend(None)
+                except StopAsyncIteration:
+                    return False
+                else:
+                    raise RuntimeError("async generator didn't stop")
+            else:
+                # It used to be possible to have type != None, value == None:
+                #    https://bugs.python.org/issue1705170
+                # but AFAICT this can't happen anymore.
+                assert value is not None
+                try:
+                    await self._agen.athrow(type, value, traceback)
+                    raise RuntimeError(
+                        "async generator didn't stop after athrow()"
+                    )
+                except StopAsyncIteration as exc:
+                    # Suppress StopIteration *unless* it's the same exception
+                    # that was passed to throw(). This prevents a
+                    # StopIteration raised inside the "with" statement from
+                    # being suppressed.
+                    return (exc is not value)
+                except RuntimeError as exc:
+                    # Don't re-raise the passed in exception. (issue27112)
+                    if exc is value:
+                        return False
+                    # Likewise, avoid suppressing if a StopIteration exception
+                    # was passed to throw() and later wrapped into a
+                    # RuntimeError (see PEP 479).
+                    if (isinstance(value, (StopIteration, StopAsyncIteration))
+                            and exc.__cause__ is value):
+                        return False
+                    raise
+                except:
+                    # only re-raise if it's *not* the exception that was
+                    # passed to throw(), because __exit__() must not raise an
+                    # exception unless __exit__() itself failed. But throw()
+                    # has to raise the exception to signal propagation, so
+                    # this fixes the impedance mismatch between the throw()
+                    # protocol and the __exit__() protocol.
+                    #
+                    if sys.exc_info()[1] is value:
+                        return False
+                    raise
+
+    def __enter__(self):
+        raise RuntimeError(
+            "use 'async with {func_name}(...)', not 'with {func_name}(...)'".
+            format(func_name=self._func_name)
+        )
+
+    def __exit__(self):  # pragma: no cover
+        assert False, """Never called, but should be defined"""
+
+
+def asynccontextmanager(func):
+    """Like @contextmanager, but async."""
+    if not isasyncgenfunction(func):
+        raise TypeError(
+            "must be an async generator (native or from async_generator; "
+            "if using @async_generator then @acontextmanager must be on top."
+        )
+
+    @wraps(func)
+    def helper(*args, **kwds):
+        return _AsyncGeneratorContextManager(func, args, kwds)
+
+    # A hint for sphinxcontrib-trio:
+    helper.__returns_acontextmanager__ = True
+    return helper

venv/Lib/site-packages/async_generator/_version.py

@@ -0,0 +1 @@
+__version__ = "1.10"