Twisted 21.2.0

An asynchronous networking framework written in Python

For information on changes in this release, see the NEWS file.

What is this?

Twisted is an event-based framework for internet applications, supporting Python 3.5+. It includes modules for many different purposes, including the following:

• twisted.web: HTTP clients and servers, HTML templating, and a WSGI server
• twisted.conch: SSHv2 and Telnet clients and servers and terminal emulators
• twisted.words: Clients and servers for IRC, XMPP, and other IM protocols
• twisted.mail: IMAPv4, POP3, SMTP clients and servers
• twisted.positioning: Tools for communicating with NMEA-compatible GPS receivers
• twisted.names: DNS client and tools for making your own DNS servers
• twisted.trial: A unit testing framework that integrates well with Twisted-based code.

Twisted supports all major system event loops – select (all platforms), poll (most POSIX platforms), epoll (Linux), kqueue (FreeBSD, macOS), IOCP (Windows), and various GUI event loops (GTK+2/3, Qt, wxWidgets). Third-party reactors can plug into Twisted, and provide support for additional event loops.

Installing

To install the latest version of Twisted using pip:

$ pip install twisted

Additional instructions for installing this software are in the installation instructions.

Documentation and Support

Twisted’s documentation is available from the Twisted Matrix website. This documentation contains how-tos, code examples, and an API reference.

Help is also available on the Twisted mailing list.

There is also a pair of very lively IRC channels, #twisted (for general Twisted questions) and #twisted.web (for Twisted Web), on chat.freenode.net.

Unit Tests

Twisted has a comprehensive test suite, which can be run by tox:

$ tox -l                       # to view all test environments
$ tox -e nocov                 # to run all the tests without coverage
$ tox -e withcov               # to run all the tests with coverage
$ tox -e alldeps-withcov-posix # install all dependencies, run tests with coverage on POSIX platform

You can test running the test suite under the different reactors with the TWISTED_REACTOR environment variable:

$ env TWISTED_REACTOR=epoll tox -e alldeps-withcov-posix

Some of these tests may fail if you:

• don’t have the dependencies required for a particular subsystem installed,
• have a firewall blocking some ports (or things like Multicast, which Linux NAT has shown itself to do), or
• run them as root.

Static Code Checkers

You can ensure that code complies to Twisted coding standards:

$ tox -e lint   # run pre-commit to check coding stanards
$ tox -e mypy   # run MyPy static type checker to check for type errors

Or, for speed, use pre-commit directly:

$ pipx run pre-commit run

Copyright

All of the code in this distribution is Copyright (c) 2001-2021 Twisted Matrix Laboratories.

Twisted is made available under the MIT license. The included LICENSE file describes this in detail.

Warranty

THIS SOFTWARE IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE USE OF THIS SOFTWARE IS WITH YOU.

IN NO EVENT WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE LIBRARY, BE LIABLE TO YOU FOR ANY DAMAGES, EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Again, see the included LICENSE file for specific legal details.