Crochet: Use Twisted anywhere!

Crochet is an MIT-licensed library that makes it easier to use Twisted from regular blocking code. Some use cases include:

• Easily use Twisted from a blocking framework like Django or Flask.
• Write a library that provides a blocking API, but uses Twisted for its implementation.
• Port blocking code to Twisted more easily, by keeping a backwards compatibility layer.
• Allow normal Twisted programs that use threads to interact with Twisted more cleanly from their threaded parts. For example, this can be useful when using Twisted as a

  WSGI container

  _.

.. _WSGI container: https://twistedmatrix.com/documents/current/web/howto/web-in-60/wsgi.html

Crochet is maintained by Itamar Turner-Trauring.

Note: Crochet development is pretty slow these days because mostly it Just Works. PyPI shows about 30,000 downloads a month, so existing users seem happy: https://pypistats.org/packages/crochet

You can install Crochet by running::

$ pip install crochet

Downloads are available on

PyPI

Documentation can be found on

Read The Docs

Bugs and feature requests should be filed at the project

Github page

.. _Read the Docs: https://crochet.readthedocs.org/ .. _Github page: https://github.com/itamarst/crochet/ .. _PyPI: https://pypi.python.org/pypi/crochet

API and features

Crochet supports Python 3.6, 3.7, 3.8, and 3.9 as well as PyPy3. Python 2.7 and 3.5 support is available in older releases.

Crochet provides the following basic APIs:

• Allow blocking code to call into Twisted and block until results are available or a timeout is hit, using the

  crochet.wait_for

  decorator.
• A lower-level API (

  crochet.run_in_reactor

  ) allows blocking code to run code "in the background" in the Twisted thread, with the ability to repeatedly check if it's done.

Crochet will do the following on your behalf in order to enable these APIs:

• Transparently start Twisted's reactor in a thread it manages.
• Shut down the reactor automatically when the process' main thread finishes.
• Hook up Twisted's log system to the Python standard library

  logging

  framework. Unlike Twisted's built-in

  logging

  bridge, this includes support for blocking

  Handler

  instances.