Metadata-Version: 2.1
Name: async-timeout
Version: 4.0.0
Summary: Timeout context manager for asyncio programs
Home-page: https://github.com/aio-libs/async_timeout/
Author: Andrew Svetlov
Author-email: andrew.svetlov@gmail.com
License: Apache 2
Platform: UNKNOWN
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: 3.10
Classifier: Topic :: Internet :: WWW/HTTP
Classifier: Framework :: AsyncIO
Requires-Python: >=3.6
Requires-Dist: typing-extensions (>=3.6.5)

async-timeout
=============
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asyncio-compatible timeout context manager.


Usage example
-------------


The context manager is useful in cases when you want to apply timeout
logic around block of code or in cases when ``asyncio.wait_for()`` is
not suitable. Also it's much faster than ``asyncio.wait_for()``
because ``timeout`` doesn't create a new task.

The ``timeout(delay, *, loop=None)`` call returns a context manager
that cancels a block on *timeout* expiring::

   async with timeout(1.5):
       await inner()

1. If ``inner()`` is executed faster than in ``1.5`` seconds nothing
   happens.
2. Otherwise ``inner()`` is cancelled internally by sending
   ``asyncio.CancelledError`` into but ``asyncio.TimeoutError`` is
   raised outside of context manager scope.

*timeout* parameter could be ``None`` for skipping timeout functionality.


Alternatively, ``timeout_at(when)`` can be used for scheduling
at the absolute time::

   loop = asyncio.get_event_loop()
   now = loop.time()

   async with timeout_at(now + 1.5):
       await inner()


Please note: it is not POSIX time but a time with
undefined starting base, e.g. the time of the system power on.


Context manager has ``.expired`` property for check if timeout happens
exactly in context manager::

   async with timeout(1.5) as cm:
       await inner()
   print(cm.expired)

The property is ``True`` if ``inner()`` execution is cancelled by
timeout context manager.

If ``inner()`` call explicitly raises ``TimeoutError`` ``cm.expired``
is ``False``.

The scheduled deadline time is available as ``.deadline`` property::

   async with timeout(1.5) as cm:
       cm.deadline

Not finished yet timeout can be rescheduled by ``shift_by()``
or ``shift_to()`` methods::

   async with timeout(1.5) as cm:
       cm.shift(1)  # add another second on waiting
       cm.update(loop.time() + 5)  # reschedule to now+5 seconds

Rescheduling is forbidden if the timeout is expired or after exit from ``async with``
code block.


Installation
------------

::

   $ pip install async-timeout

The library is Python 3 only!



Authors and License
-------------------

The module is written by Andrew Svetlov.

It's *Apache 2* licensed and freely available.


CHANGES
=======

4.0.0 (2021-11-01)
------------------

* Implemented ``timeout_at(deadline)`` (#117)

* Supported ``timeout.deadline`` and ``timeout.expired`` properties.

* Drooped ``timeout.remaining`` property: it can be calculated as
  ``timeout.deadline - loop.time()``

* Dropped ``timeout.timeout`` property that returns a relative timeout based on the
  timeout object creation time; the absolute ``timeout.deadline`` should be used
  instead.

* Added the deadline modification methods: ``timeout.reject()``,
  ``timeout.shift(delay)``, ``timeout.update(deadline)``.

* Deprecated synchronous context manager usage

3.0.1 (2018-10-09)
------------------

* More aggressive typing (#48)

3.0.0 (2018-05-05)
------------------

* Drop Python 3.4, the minimal supported version is Python 3.5.3

* Provide type annotations

2.0.1 (2018-03-13)
------------------

* Fix ``PendingDeprecationWarning`` on Python 3.7 (#33)


2.0.0 (2017-10-09)
------------------

* Changed ``timeout <= 0`` behaviour

  * Backward incompatibility change, prior this version ``0`` was
    shortcut for ``None``
  * when timeout <= 0 ``TimeoutError`` raised faster

1.4.0 (2017-09-09)
------------------

* Implement ``remaining`` property (#20)

  * If timeout is not started yet or started unconstrained:
    ``remaining`` is ``None``
  * If timeout is expired: ``remaining`` is ``0.0``
  * All others: roughly amount of time before ``TimeoutError`` is triggered

1.3.0 (2017-08-23)
------------------

* Don't suppress nested exception on timeout. Exception context points
  on cancelled line with suspended ``await`` (#13)

* Introduce ``.timeout`` property (#16)

* Add methods for using as async context manager (#9)

1.2.1 (2017-05-02)
------------------

* Support unpublished event loop's "current_task" api.


1.2.0 (2017-03-11)
------------------

* Extra check on context manager exit

* 0 is no-op timeout


1.1.0 (2016-10-20)
------------------

* Rename to ``async-timeout``

1.0.0 (2016-09-09)
------------------

* The first release.


