Merge pull request #34 from ncoghlan/issue-33-add-type-hinting-support

Issue #33: convert to package and include typeshed type hints

CONTRIBUTING.md

@@ -1,3 +1,5 @@
 [![Jazzband](https://jazzband.co/static/img/jazzband.svg)](https://jazzband.co/)
 
-This is a [Jazzband](https://jazzband.co/) project. By contributing you agree to abide by the [Contributor Code of Conduct](https://jazzband.co/about/conduct) and follow the [guidelines](https://jazzband.co/about/guidelines).
+This is a [Jazzband](https://jazzband.co/) project. By contributing you agree
+to abide by the [Contributor Code of Conduct](https://jazzband.co/about/conduct)
+and follow the [guidelines](https://jazzband.co/about/guidelines).

LICENSE.txt

@@ -1,4 +1,6 @@
-
+Note: The type hints included in this package come from the typeshed project,
+and are hence distributed under the Apache License 2.0 rather than under the
+Python Software License that covers the module implementation and test suite.
 
 A. HISTORY OF THE SOFTWARE
 ==========================

MANIFEST.in

@@ -1,2 +1,5 @@
-include *.py *.txt *.rst *.md *.ini MANIFEST.in
-recursive-include dev test docs *.rst *.py make.bat Makefile
+include *.py *.cfg *.txt *.rst *.md *.ini MANIFEST.in
+recursive-include contextlib2 *.py *.pyi py.typed
+recursive-include docs *.rst *.py make.bat Makefile
+recursive-include test *.py
+recursive-include dev *.patch

NEWS.rst

@@ -4,8 +4,12 @@ Release History
 21.6.0 (2021-06-27)
 ^^^^^^^^^^^^^^^^^^^
 
-* Switched to calendar based versioning rather than continuing with pre-1.0
-  semantic versioning (`#29 <https://github.com/jazzband/contextlib2/issues/29>`__)
+* License update: due to the inclusion of type hints from the ``typeshed``
+  project, the ``contextlib2`` project is now under a combination of the
+  Python Software License (existing license) and the Apache License 2.0
+  (``typeshed`` license)
+* Switched to calendar based versioning using a "year"-"month"-"serial" scheme,
+  rather than continuing with pre-1.0 semantic versioning
 * Due to the inclusion of asynchronous features from Python 3.7+, the
   minimum supported Python version is now Python 3.6
   (`#29 <https://github.com/jazzband/contextlib2/issues/29>`__)
@@ -20,6 +24,12 @@ Release History
   * ``AsyncExitStack`` (added in Python 3.7)
   * async support in ``nullcontext`` (Python 3.10)
 
+* ``contextlib2`` now includes an adapted copy of the ``contextlib``
+  type hints from ``typeshed`` (the adaptation removes the Python version
+  dependencies from the API definition)
+  (`#33 <https://github.com/jazzband/contextlib2/issues/33>`__)
+* to incorporate the type hints stub file and the ``py.typed`` marker file,
+  ``contextlib2`` is now installed as a package rather than as a module
 * Updates to the default compatibility testing matrix:
 
   * Added: CPython 3.9, CPython 3.10

README.rst

@@ -18,9 +18,19 @@ contextlib2 is a backport of the `standard library's contextlib
 module <https://docs.python.org/3/library/contextlib.html>`_ to
 earlier Python versions.
 
-It also serves as a real world proving ground for possible future
+It also sometimes serves as a real world proving ground for possible future
 enhancements to the standard library version.
 
+Licensing
+---------
+
+As a backport of Python standard library software, the implementation, test
+suite and other supporting files for this project are distributed under the
+Python Software License used for the CPython reference implementation.
+
+The one exception is the included type hints file, which comes from the
+``typeshed`` project, and is hence distributed under the Apache License 2.0.
+
 Development
 -----------
 
@@ -50,18 +60,32 @@ Versions currently tested in both tox and GitHub Actions are:
 Updating to a new stdlib reference version
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-As of Python 3.10, 3 files needed to be copied from the CPython reference
+As of Python 3.10, 4 files needed to be copied from the CPython reference
 implementation to contextlib2:
 
-* ``Lib/contextlib.py`` -> ``contextlib2.py``
+* ``Doc/contextlib.rst`` -> ``docs/contextlib2.rst``
+* ``Lib/contextlib.py`` -> ``contextlib2/__init__.py``
 * ``Lib/test/test_contextlib.py`` -> ``test/test_contextlib.py``
 * ``Lib/test/test_contextlib_async.py`` -> ``test/test_contextlib_async.py``
 
+The corresponding version of ``contextlib2/__init__.pyi`` also needs to be
+retrieved from the ``typeshed`` project::
+
+    wget https://raw.githubusercontent.com/python/typeshed/master/stdlib/contextlib.pyi
+
 For the 3.10 sync, the only changes needed to the test files were to import from
 ``contextlib2`` rather than ``contextlib``. The test directory is laid out so
 that the test suite's imports from ``test.support`` work the same way they do in
 the main CPython test suite.
 
-The changes made to the ``contextlib2.py`` file to get it to run on the older
-versions (and to add back in the deprecated APIs that never graduated to the
-standard library version) are saved as a patch file in the ``dev`` directory.
+The following patch files are saved in the ``dev`` directory:
+
+* changes made to ``contextlib2/__init__.py`` to get it to run on the older
+  versions (and to add back in the deprecated APIs that never graduated to
+  the standard library version)
+* changes made to ``contextlib2/__init__.pyi`` to make the Python version
+  guards unconditional (since the ``contextlib2`` API is the same on all
+  supported versions)
+* changes made to ``docs/contextlib2.rst`` to use ``contextlib2`` version
+  numbers in the version added/changed notes and to integrate the module
+  documentation with the rest of the project documentation

contextlib2/__init__.pyi

@@ -0,0 +1,125 @@
+# Type hints copied from the typeshed project under the Apache License 2.0
+# https://github.com/python/typeshed/blob/64c85cdd449ccaff90b546676220c9ecfa6e697f/LICENSE
+
+import sys
+from types import TracebackType
+from typing import (
+    IO,
+    Any,
+    AsyncContextManager,
+    AsyncIterator,
+    Awaitable,
+    Callable,
+    ContextManager,
+    Iterator,
+    Optional,
+    Type,
+    TypeVar,
+    overload,
+)
+from typing_extensions import ParamSpec, Protocol
+
+# Note: the various 'if True:' guards replace sys.version checks in the
+# original typeshed file that don't apply to the contextlib2 backport API
+
+AbstractContextManager = ContextManager
+if True:
+    AbstractAsyncContextManager = AsyncContextManager
+
+_T = TypeVar("_T")
+_T_co = TypeVar("_T_co", covariant=True)
+_T_io = TypeVar("_T_io", bound=Optional[IO[str]])
+_F = TypeVar("_F", bound=Callable[..., Any])
+_P = ParamSpec("_P")
+
+_ExitFunc = Callable[[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]], bool]
+_CM_EF = TypeVar("_CM_EF", ContextManager[Any], _ExitFunc)
+
+class _GeneratorContextManager(ContextManager[_T_co]):
+    def __call__(self, func: _F) -> _F: ...
+
+# type ignore to deal with incomplete ParamSpec support in mypy
+def contextmanager(func: Callable[_P, Iterator[_T]]) -> Callable[_P, _GeneratorContextManager[_T]]: ...  # type: ignore
+
+if True:
+    def asynccontextmanager(func: Callable[_P, AsyncIterator[_T]]) -> Callable[_P, AsyncContextManager[_T]]: ...  # type: ignore
+
+class _SupportsClose(Protocol):
+    def close(self) -> object: ...
+
+_SupportsCloseT = TypeVar("_SupportsCloseT", bound=_SupportsClose)
+
+class closing(ContextManager[_SupportsCloseT]):
+    def __init__(self, thing: _SupportsCloseT) -> None: ...
+
+if True:
+    class _SupportsAclose(Protocol):
+        async def aclose(self) -> object: ...
+    _SupportsAcloseT = TypeVar("_SupportsAcloseT", bound=_SupportsAclose)
+    class aclosing(AsyncContextManager[_SupportsAcloseT]):
+        def __init__(self, thing: _SupportsAcloseT) -> None: ...
+    _AF = TypeVar("_AF", bound=Callable[..., Awaitable[Any]])
+    class AsyncContextDecorator:
+        def __call__(self, func: _AF) -> _AF: ...
+
+class suppress(ContextManager[None]):
+    def __init__(self, *exceptions: Type[BaseException]) -> None: ...
+    def __exit__(
+        self, exctype: Optional[Type[BaseException]], excinst: Optional[BaseException], exctb: Optional[TracebackType]
+    ) -> bool: ...
+
+class redirect_stdout(ContextManager[_T_io]):
+    def __init__(self, new_target: _T_io) -> None: ...
+
+class redirect_stderr(ContextManager[_T_io]):
+    def __init__(self, new_target: _T_io) -> None: ...
+
+class ContextDecorator:
+    def __call__(self, func: _F) -> _F: ...
+
+_U = TypeVar("_U", bound=ExitStack)
+
+class ExitStack(ContextManager[ExitStack]):
+    def __init__(self) -> None: ...
+    def enter_context(self, cm: ContextManager[_T]) -> _T: ...
+    def push(self, exit: _CM_EF) -> _CM_EF: ...
+    def callback(self, callback: Callable[..., Any], *args: Any, **kwds: Any) -> Callable[..., Any]: ...
+    def pop_all(self: _U) -> _U: ...
+    def close(self) -> None: ...
+    def __enter__(self: _U) -> _U: ...
+    def __exit__(
+        self,
+        __exc_type: Optional[Type[BaseException]],
+        __exc_value: Optional[BaseException],
+        __traceback: Optional[TracebackType],
+    ) -> bool: ...
+
+if True:
+    _S = TypeVar("_S", bound=AsyncExitStack)
+
+    _ExitCoroFunc = Callable[[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]], Awaitable[bool]]
+    _CallbackCoroFunc = Callable[..., Awaitable[Any]]
+    _ACM_EF = TypeVar("_ACM_EF", AsyncContextManager[Any], _ExitCoroFunc)
+    class AsyncExitStack(AsyncContextManager[AsyncExitStack]):
+        def __init__(self) -> None: ...
+        def enter_context(self, cm: ContextManager[_T]) -> _T: ...
+        def enter_async_context(self, cm: AsyncContextManager[_T]) -> Awaitable[_T]: ...
+        def push(self, exit: _CM_EF) -> _CM_EF: ...
+        def push_async_exit(self, exit: _ACM_EF) -> _ACM_EF: ...
+        def callback(self, callback: Callable[..., Any], *args: Any, **kwds: Any) -> Callable[..., Any]: ...
+        def push_async_callback(self, callback: _CallbackCoroFunc, *args: Any, **kwds: Any) -> _CallbackCoroFunc: ...
+        def pop_all(self: _S) -> _S: ...
+        def aclose(self) -> Awaitable[None]: ...
+        def __aenter__(self: _S) -> Awaitable[_S]: ...
+        def __aexit__(
+            self,
+            __exc_type: Optional[Type[BaseException]],
+            __exc_value: Optional[BaseException],
+            __traceback: Optional[TracebackType],
+        ) -> Awaitable[bool]: ...
+
+if True:
+    @overload
+    def nullcontext(enter_result: _T) -> ContextManager[_T]: ...
+    @overload
+    def nullcontext() -> ContextManager[None]: ...

dev/py3_10_contextlib_pyi_to_contextlib2_pyi.patch

@@ -0,0 +1,58 @@
+--- ../contextlib.pyi	2021-06-26 21:36:16.491964153 +1000
++++ contextlib2/__init__.pyi	2021-06-26 21:41:08.109598690 +1000
+@@ -1,3 +1,6 @@
++# Type hints copied from the typeshed project under the Apache License 2.0
++# https://github.com/python/typeshed/blob/64c85cdd449ccaff90b546676220c9ecfa6e697f/LICENSE
++
+ import sys
+ from types import TracebackType
+ from typing import (
+@@ -16,8 +19,11 @@
+ )
+ from typing_extensions import ParamSpec, Protocol
+
++# Note: the various 'if True:' guards replace sys.version checks in the
++# original typeshed file that don't apply to the contextlib2 backport API
++
+ AbstractContextManager = ContextManager
+-if sys.version_info >= (3, 7):
++if True:
+     AbstractAsyncContextManager = AsyncContextManager
+
+ _T = TypeVar("_T")
+@@ -35,7 +41,7 @@
+ # type ignore to deal with incomplete ParamSpec support in mypy
+ def contextmanager(func: Callable[_P, Iterator[_T]]) -> Callable[_P, _GeneratorContextManager[_T]]: ...  # type: ignore
+
+-if sys.version_info >= (3, 7):
++if True:
+     def asynccontextmanager(func: Callable[_P, AsyncIterator[_T]]) -> Callable[_P, AsyncContextManager[_T]]: ...  # type: ignore
+
+ class _SupportsClose(Protocol):
+@@ -46,7 +52,7 @@
+ class closing(ContextManager[_SupportsCloseT]):
+     def __init__(self, thing: _SupportsCloseT) -> None: ...
+
+-if sys.version_info >= (3, 10):
++if True:
+     class _SupportsAclose(Protocol):
+         async def aclose(self) -> object: ...
+     _SupportsAcloseT = TypeVar("_SupportsAcloseT", bound=_SupportsAclose)
+@@ -88,7 +94,7 @@
+         __traceback: Optional[TracebackType],
+     ) -> bool: ...
+
+-if sys.version_info >= (3, 7):
++if True:
+     _S = TypeVar("_S", bound=AsyncExitStack)
+
+     _ExitCoroFunc = Callable[[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]], Awaitable[bool]]
+@@ -112,7 +118,7 @@
+             __traceback: Optional[TracebackType],
+         ) -> Awaitable[bool]: ...
+
+-if sys.version_info >= (3, 7):
++if True:
+     @overload
+     def nullcontext(enter_result: _T) -> ContextManager[_T]: ...
+     @overload

setup.py

@@ -8,7 +8,8 @@
     name='contextlib2',
     version=open('VERSION.txt').read().strip(),
     python_requires='>=3.6',
-    py_modules=['contextlib2'],
+    packages=['contextlib2'],
+    include_package_data=True,
     license='PSF License',
     description='Backports and enhancements for the contextlib module',
     long_description=open('README.rst').read(),
@@ -17,6 +18,7 @@
     url='http://contextlib2.readthedocs.org',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
+        'License :: OSI Approved :: Apache Software License',
         'License :: OSI Approved :: Python Software Foundation License',
         # These are the Python versions tested, it may work on others
         # It definitely won't work on versions without native async support

tox.ini

@@ -7,8 +7,11 @@ commands =
     coverage run -m unittest discover -t . -s test
     coverage report
     coverage xml
+    # mypy won't install on PyPy, so only run the typechecking on CPython
+    !pypy3: mypy contextlib2
 deps =
     coverage
+    !pypy3: mypy
 
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