Sign inDemoInstall


Package Overview
File Explorer

Install Socket

Detect and block malicious and high-risk dependencies



reference implementation of PEP 3156



This version is only relevant for Python 3.3, which does not include asyncio in its stdlib.

Master repo:

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 <>_: source code, bug tracker
  • asyncio documentation <>_
  • Mailing list: python-tulip Google Group <!forum/python-tulip>_
  • IRC: join the #asyncio channel 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::

make test

To run coverage (coverage package is required)::

make coverage

On Windows, things are a little more complicated. Assume 'P' is your Python binary (for example C:\Python33\python.exe).

You must first build the _overlapped.pyd extension and have it placed in the asyncio directory, as follows:

C> P 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 (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

And coverage as follows:

C> P --coverage


Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.


Related posts

SocketSocket SOC 2 Logo


  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Stay in touch

Get open source security insights delivered straight into your inbox.

  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc