Lines Matching +full:async +full:- +full:io

1 :mod:`!contextlib` --- Utilities for :keyword:`!with`\ -statement contexts
5    :synopsis: Utilities for with-statement contexts.
9 --------------
13 :ref:`context-managers`.
17 ---------
39    :ref:`async-context-managers`.
75    The function being decorated must return a :term:`generator`-iterator when
94    each function call (this allows the otherwise "one-shot" context managers
105    :ref:`asynchronous context manager <async-context-managers>`.
108    function for :keyword:`async with` statement asynchronous context managers,
118       async def get_connection():
125       async def get_all_users():
126           async with get_connection() as conn:
132    either as decorators or with :keyword:`async with` statements::
138      async def timeit():
143              print(f'it took {time.monotonic() - now}s to run')
146      async def main():
147          # ... async code ...
150    each function call. This allows the otherwise "one-shot" context managers
155      Async context managers created with :func:`asynccontextmanager` can
188    Return an async context manager that calls the ``aclose()`` method of *thing*
194       async def aclosing(thing):
200    Significantly, ``aclosing()`` supports deterministic cleanup of async
206       async with aclosing(my_generator()) as values:
207           async for value in values:
211    This pattern ensures that the generator's async exit code is executed in
219 .. _simplifying-support-for-single-optional-context-managers:
224    otherwise does nothing. It is intended to be used as a stand-in for an
250    It can also be used as a stand-in for
251    :ref:`asynchronous context managers <async-context-managers>`::
253        async def send_http(session=None):
261            async with cm as session:
305    This context manager is :ref:`reentrant <reentrant-cms>`.
313    another file or file-like object.
320    :class:`io.StringIO` object. The replacement stream is returned from the
324         with redirect_stdout(io.StringIO()) as f:
345    This context manager is :ref:`reentrant <reentrant-cms>`.
353    :data:`sys.stderr` to another file or file-like object.
355    This context manager is :ref:`reentrant <reentrant-cms>`.
362    Non parallel-safe context manager to change the current working directory.
364    for use in most threaded or async contexts. It is also not suitable for most
365    non-linear code execution, like generators, where the program execution is
366    temporarily relinquished -- unless explicitly desired, you should not yield
372    This context manager is :ref:`reentrant <reentrant-cms>`.
465           async def __aenter__(self):
469           async def __aexit__(self, *exc):
476       ... async def function():
484       >>> async def function():
485       ...    async with mycontext():
526    extends to exception handling - if an inner callback suppresses or replaces
582       and returns it. No callbacks are invoked by this operation - instead,
607    An :ref:`asynchronous context manager <async-context-managers>`, similar
639       async with AsyncExitStack() as stack:
643           # the async with statement, even if attempts to open a connection
649 --------------------
751 Replacing any use of ``try-finally`` and flag variables
754 A pattern you will sometimes see is a ``try-finally`` statement with a flag
872    :pep:`343` - The "with" statement
876 .. _single-use-reusable-and-reentrant-cms:
879 ---------------------------------------------------
883 context managers must be created afresh each time they're used -
893 further IO operations using that file object.
920 .. _reentrant-cms:
935     >>> from io import StringIO
959 .. _reusable-cms: