The asyncio module provides infrastructure for writing single-threaded concurrent code using coroutines, multiplexing I/O access over sockets and other resources, running network clients and servers, and other related primitives. Here is a more detailed list of the package contents:
a pluggable event loop with various system-specific implementations;
transport and protocol abstractions (similar to those in Twisted);
concrete support for TCP, UDP, SSL, subprocess pipes, delayed calls, and others (some may be system-dependent);
a Future class that mimics the one in the concurrent.futures module, but adapted for use with the event loop;
coroutines and tasks based on
yield from(PEP 380), to help write concurrent code in a sequential fashion;
cancellation support for Futures and coroutines;
synchronization primitives for use between coroutines in a single thread, mimicking those in the threading module;
an interface for passing work off to a threadpool, for times when you absolutely, positively have to use a library that makes blocking I/O calls.
Note: The implementation of asyncio was previously called “Tulip”.
To install asyncio, type::
pip install asyncio
asyncio requires Python 3.3 or later! The asyncio module is part of the Python standard library since Python 3.4.
asyncio is a free software distributed under the Apache license version 2.0.
asyncio project at GitHub <https://github.com/python/asyncio>_: source code, bug tracker
asyncio documentation <https://docs.python.org/dev/library/asyncio.html>_
- Mailing list:
python-tulip Google Group <https://groups.google.com/forum/?fromgroups#!forum/python-tulip>_
- IRC: join the
#asynciochannel on the Freenode network
The actual code lives in the ‘asyncio’ subdirectory. Tests are in the ‘tests’ subdirectory.
To run tests, run::
Or use the Makefile::
To run coverage (coverage package is required)::
On Windows, things are a little more complicated. Assume
P is your
Python binary (for example
You must first build the _overlapped.pyd extension and have it placed in the asyncio directory, as follows::
C:\> P setup.py build_ext --inplace
If this complains about vcvars.bat, you probably don’t have the required version of Visual Studio installed. Compiling extensions for Python 3.3 requires Microsoft Visual C++ 2010 (MSVC 10.0) of any edition; you can download Visual Studio Express 2010 for free from http://www.visualstudio.com/downloads (scroll down to Visual C++ 2010 Express).
Once you have built the _overlapped.pyd extension successfully you can run the tests as follows::
C:\> P runtests.py
And coverage as follows::
C:\> P runtests.py --coverage