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contextlib2/dev/py3_12_rst_to_contextlib2.patch
Nick Coghlan fa85611aec Fix refs to contextlib, update diffs
2024-05-23 17:41:07 +10:00

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--- /home/ncoghlan/devel/contextlib2/../cpython/Doc/library/contextlib.rst 2024-05-20 12:53:59.936907756 +1000
+++ /home/ncoghlan/devel/contextlib2/docs/contextlib2.rst 2024-05-23 17:39:52.671083724 +1000
@@ -1,20 +1,5 @@
-:mod:`!contextlib` --- Utilities for :keyword:`!with`\ -statement contexts
-==========================================================================
-
-.. module:: contextlib
- :synopsis: Utilities for with-statement contexts.
-
-**Source code:** :source:`Lib/contextlib.py`
-
---------------
-
-This module provides utilities for common tasks involving the :keyword:`with`
-statement. For more information see also :ref:`typecontextmanager` and
-:ref:`context-managers`.
-
-
-Utilities
----------
+API Reference
+-------------
Functions and classes provided:
@@ -26,8 +11,8 @@
``self`` while :meth:`object.__exit__` is an abstract method which by default
returns ``None``. See also the definition of :ref:`typecontextmanager`.
- .. versionadded:: 3.6
-
+ .. versionadded:: 0.6.0
+ Part of the standard library in Python 3.6 and later
.. class:: AbstractAsyncContextManager
@@ -38,8 +23,8 @@
returns ``None``. See also the definition of
:ref:`async-context-managers`.
- .. versionadded:: 3.7
-
+ .. versionadded:: 21.6.0
+ Part of the standard library in Python 3.7 and later
.. decorator:: contextmanager
@@ -49,12 +34,12 @@
While many objects natively support use in with statements, sometimes a
resource needs to be managed that isn't a context manager in its own right,
- and doesn't implement a ``close()`` method for use with ``contextlib.closing``
+ and doesn't implement a ``close()`` method for use with ``contextlib2.closing``
An abstract example would be the following to ensure correct resource
management::
- from contextlib import contextmanager
+ from contextlib2 import contextmanager
@contextmanager
def managed_resource(*args, **kwds):
@@ -95,13 +80,10 @@
created by :func:`contextmanager` to meet the requirement that context
managers support multiple invocations in order to be used as decorators).
- .. versionchanged:: 3.2
- Use of :class:`ContextDecorator`.
-
.. decorator:: asynccontextmanager
- Similar to :func:`~contextlib.contextmanager`, but creates an
+ Similar to :func:`~contextlib2.contextmanager`, but creates an
:ref:`asynchronous context manager <async-context-managers>`.
This function is a :term:`decorator` that can be used to define a factory
@@ -112,7 +94,7 @@
A simple example::
- from contextlib import asynccontextmanager
+ from contextlib2 import asynccontextmanager
@asynccontextmanager
async def get_connection():
@@ -126,13 +108,16 @@
async with get_connection() as conn:
return conn.query('SELECT ...')
- .. versionadded:: 3.7
+ .. versionadded:: 21.6.0
+ Part of the standard library in Python 3.7 and later, enhanced in
+ Python 3.10 and later to allow created async context managers to be used
+ as async function decorators.
Context managers defined with :func:`asynccontextmanager` can be used
either as decorators or with :keyword:`async with` statements::
import time
- from contextlib import asynccontextmanager
+ from contextlib2 import asynccontextmanager
@asynccontextmanager
async def timeit():
@@ -151,17 +136,13 @@
created by :func:`asynccontextmanager` to meet the requirement that context
managers support multiple invocations in order to be used as decorators.
- .. versionchanged:: 3.10
- Async context managers created with :func:`asynccontextmanager` can
- be used as decorators.
-
.. function:: closing(thing)
Return a context manager that closes *thing* upon completion of the block. This
is basically equivalent to::
- from contextlib import contextmanager
+ from contextlib2 import contextmanager
@contextmanager
def closing(thing):
@@ -172,7 +153,7 @@
And lets you write code like this::
- from contextlib import closing
+ from contextlib2 import closing
from urllib.request import urlopen
with closing(urlopen('https://www.python.org')) as page:
@@ -196,7 +177,7 @@
Return an async context manager that calls the ``aclose()`` method of *thing*
upon completion of the block. This is basically equivalent to::
- from contextlib import asynccontextmanager
+ from contextlib2 import asynccontextmanager
@asynccontextmanager
async def aclosing(thing):
@@ -209,7 +190,7 @@
generators when they happen to exit early by :keyword:`break` or an
exception. For example::
- from contextlib import aclosing
+ from contextlib2 import aclosing
async with aclosing(my_generator()) as values:
async for value in values:
@@ -221,7 +202,8 @@
variables work as expected, and the exit code isn't run after the
lifetime of some task it depends on).
- .. versionadded:: 3.10
+ .. versionadded:: 21.6.0
+ Part of the standard library in Python 3.10 and later
.. _simplifying-support-for-single-optional-context-managers:
@@ -235,10 +217,10 @@
def myfunction(arg, ignore_exceptions=False):
if ignore_exceptions:
# Use suppress to ignore all exceptions.
- cm = contextlib.suppress(Exception)
+ cm = contextlib2.suppress(Exception)
else:
# Do not ignore any exceptions, cm has no effect.
- cm = contextlib.nullcontext()
+ cm = contextlib2.nullcontext()
with cm:
# Do something
@@ -269,11 +251,11 @@
async with cm as session:
# Send http requests with session
- .. versionadded:: 3.7
-
- .. versionchanged:: 3.10
- :term:`asynchronous context manager` support was added.
+ .. versionadded:: 0.6.0
+ Part of the standard library in Python 3.7 and later
+ .. versionchanged:: 21.6.0
+ Updated to Python 3.10 version with :term:`asynchronous context manager` support
.. function:: suppress(*exceptions)
@@ -290,7 +272,7 @@
For example::
- from contextlib import suppress
+ from contextlib2 import suppress
with suppress(FileNotFoundError):
os.remove('somefile.tmp')
@@ -314,13 +296,15 @@
If the code within the :keyword:`!with` block raises a
:exc:`BaseExceptionGroup`, suppressed exceptions are removed from the
- group. If any exceptions in the group are not suppressed, a group containing them is re-raised.
+ group. If any exceptions in the group are not suppressed, a group containing
+ them is re-raised.
- .. versionadded:: 3.4
+ .. versionadded:: 0.5
+ Part of the standard library in Python 3.4 and later
- .. versionchanged:: 3.12
- ``suppress`` now supports suppressing exceptions raised as
- part of an :exc:`BaseExceptionGroup`.
+ .. versionchanged:: 24.6.0
+ Updated to Python 3.12 version that supports suppressing exceptions raised
+ as part of a :exc:`BaseExceptionGroup`.
.. function:: redirect_stdout(new_target)
@@ -359,17 +343,19 @@
This context manager is :ref:`reentrant <reentrant-cms>`.
- .. versionadded:: 3.4
+ .. versionadded:: 0.5
+ Part of the standard library in Python 3.4 and later
.. function:: redirect_stderr(new_target)
- Similar to :func:`~contextlib.redirect_stdout` but redirecting
+ Similar to :func:`~contextlib2.redirect_stdout` but redirecting
:data:`sys.stderr` to another file or file-like object.
This context manager is :ref:`reentrant <reentrant-cms>`.
- .. versionadded:: 3.5
+ .. versionadded:: 0.5
+ Part of the standard library in Python 3.5 and later
.. function:: chdir(path)
@@ -386,7 +372,8 @@
This context manager is :ref:`reentrant <reentrant-cms>`.
- .. versionadded:: 3.11
+ .. versionadded:: 24.6.0
+ Part of the standard library in Python 3.11 and later
.. class:: ContextDecorator()
@@ -402,7 +389,7 @@
Example of ``ContextDecorator``::
- from contextlib import ContextDecorator
+ from contextlib2 import ContextDecorator
class mycontext(ContextDecorator):
def __enter__(self):
@@ -449,7 +436,7 @@
Existing context managers that already have a base class can be extended by
using ``ContextDecorator`` as a mixin class::
- from contextlib import ContextDecorator
+ from contextlib2 import ContextDecorator
class mycontext(ContextBaseClass, ContextDecorator):
def __enter__(self):
@@ -464,8 +451,6 @@
statements. If this is not the case, then the original construct with the
explicit :keyword:`!with` statement inside the function should be used.
- .. versionadded:: 3.2
-
.. class:: AsyncContextDecorator
@@ -474,7 +459,7 @@
Example of ``AsyncContextDecorator``::
from asyncio import run
- from contextlib import AsyncContextDecorator
+ from contextlib2 import AsyncContextDecorator
class mycontext(AsyncContextDecorator):
async def __aenter__(self):
@@ -505,7 +490,8 @@
The bit in the middle
Finishing
- .. versionadded:: 3.10
+ .. versionadded:: 21.6.0
+ Part of the standard library in Python 3.10 and later
.. class:: ExitStack()
@@ -547,7 +533,8 @@
foundation for higher level context managers that manipulate the exit
stack in application specific ways.
- .. versionadded:: 3.3
+ .. versionadded:: 0.4
+ Part of the standard library in Python 3.3 and later
.. method:: enter_context(cm)
@@ -558,9 +545,10 @@
These context managers may suppress exceptions just as they normally
would if used directly as part of a :keyword:`with` statement.
- .. versionchanged:: 3.11
- Raises :exc:`TypeError` instead of :exc:`AttributeError` if *cm*
- is not a context manager.
+ .. versionchanged:: 24.6.0
+ When running on Python 3.11 or later, raises :exc:`TypeError` instead
+ of :exc:`AttributeError` if *cm* is not a context manager. This aligns
+ with the behaviour of :keyword:`with` statements in Python 3.11+.
.. method:: push(exit)
@@ -627,14 +615,16 @@
The :meth:`~ExitStack.close` method is not implemented; :meth:`aclose` must be used
instead.
- .. coroutinemethod:: enter_async_context(cm)
+ .. method:: enter_async_context(cm)
+ :async:
Similar to :meth:`ExitStack.enter_context` but expects an asynchronous context
manager.
- .. versionchanged:: 3.11
- Raises :exc:`TypeError` instead of :exc:`AttributeError` if *cm*
- is not an asynchronous context manager.
+ .. versionchanged:: 24.6.0
+ When running on Python 3.11 or later, raises :exc:`TypeError` instead
+ of :exc:`AttributeError` if *cm* is not an asynchronous context manager.
+ This aligns with the behaviour of ``async with`` statements in Python 3.11+.
.. method:: push_async_exit(exit)
@@ -645,7 +635,8 @@
Similar to :meth:`ExitStack.callback` but expects a coroutine function.
- .. coroutinemethod:: aclose()
+ .. method:: aclose()
+ :async:
Similar to :meth:`ExitStack.close` but properly handles awaitables.
@@ -658,13 +649,15 @@
# the async with statement, even if attempts to open a connection
# later in the list raise an exception.
- .. versionadded:: 3.7
+ .. versionadded:: 21.6.0
+ Part of the standard library in Python 3.7 and later
+
Examples and Recipes
--------------------
This section describes some examples and recipes for making effective use of
-the tools provided by :mod:`contextlib`.
+the tools provided by :mod:`contextlib2`.
Supporting a variable number of context managers
@@ -728,7 +721,7 @@
acquisition and release functions, along with an optional validation function,
and maps them to the context management protocol::
- from contextlib import contextmanager, AbstractContextManager, ExitStack
+ from contextlib2 import contextmanager, AbstractContextManager, ExitStack
class ResourceManager(AbstractContextManager):
@@ -788,7 +781,7 @@
execution at the end of a ``with`` statement, and then later decide to skip
executing that callback::
- from contextlib import ExitStack
+ from contextlib2 import ExitStack
with ExitStack() as stack:
stack.callback(cleanup_resources)
@@ -802,7 +795,7 @@
If a particular application uses this pattern a lot, it can be simplified
even further by means of a small helper class::
- from contextlib import ExitStack
+ from contextlib2 import ExitStack
class Callback(ExitStack):
def __init__(self, callback, /, *args, **kwds):
@@ -822,7 +815,7 @@
:meth:`ExitStack.callback` to declare the resource cleanup in
advance::
- from contextlib import ExitStack
+ from contextlib2 import ExitStack
with ExitStack() as stack:
@stack.callback
@@ -849,7 +842,7 @@
inheriting from :class:`ContextDecorator` provides both capabilities in a
single definition::
- from contextlib import ContextDecorator
+ from contextlib2 import ContextDecorator
import logging
logging.basicConfig(level=logging.INFO)
@@ -911,7 +904,7 @@
context managers, and will complain about the underlying generator failing
to yield if an attempt is made to use them a second time::
- >>> from contextlib import contextmanager
+ >>> from contextlib2 import contextmanager
>>> @contextmanager
... def singleuse():
... print("Before")
@@ -946,7 +939,7 @@
:func:`suppress`, :func:`redirect_stdout`, and :func:`chdir`. Here's a very
simple example of reentrant use::
- >>> from contextlib import redirect_stdout
+ >>> from contextlib2 import redirect_stdout
>>> from io import StringIO
>>> stream = StringIO()
>>> write_to_stream = redirect_stdout(stream)
@@ -992,7 +985,7 @@
when leaving any with statement, regardless of where those callbacks
were added::
- >>> from contextlib import ExitStack
+ >>> from contextlib2 import ExitStack
>>> stack = ExitStack()
>>> with stack:
... stack.callback(print, "Callback: from first context")
@@ -1026,7 +1019,7 @@
Using separate :class:`ExitStack` instances instead of reusing a single
instance avoids that problem::
- >>> from contextlib import ExitStack
+ >>> from contextlib2 import ExitStack
>>> with ExitStack() as outer_stack:
... outer_stack.callback(print, "Callback: from outer context")
... with ExitStack() as inner_stack:
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