Description

.. image:: https://img.shields.io/badge/chat-join%20now-blue.svg :target: https://gitter.im/python-trio/general :alt: Join chatroom .. image:: https://img.shields.io/badge/forum-join%20now-blue.svg :target: https://trio.discourse.group :alt: Join forum .. image:: https://img.shields.io/badge/docs-read%20now-blue.svg :target: https://trio.readthedocs.io :alt: Documentation .. image:: https://img.shields.io/pypi/v/trio.svg :target: https://pypi.org/project/trio :alt: Latest PyPi version .. image:: https://img.shields.io/conda/vn/conda-forge/trio.svg :target: https://anaconda.org/conda-forge/trio :alt: Latest conda-forge version .. image:: https://codecov.io/gh/python-trio/trio/branch/main/graph/badge.svg :target: https://codecov.io/gh/python-trio/trio :alt: Test coverage Trio – a friendly Python library for async concurrency and I/O ============================================================== .. image:: https://raw.githubusercontent.com/python-trio/trio/9b0bec646a31e0d0f67b8b6ecc6939726faf3e17/logo/logo-with-background.svg :width: 200px :align: right The Trio project aims to produce a production-quality, `permissively licensed <https://github.com/python-trio/trio/blob/main/LICENSE>`__, async/await-native I/O library for Python. Like all async libraries, its main purpose is to help you write programs that do **multiple things at the same time** with **parallelized I/O**. A web spider that wants to fetch lots of pages in parallel, a web server that needs to juggle lots of downloads and websocket connections simultaneously, a process supervisor monitoring multiple subprocesses... that sort of thing. Compared to other libraries, Trio attempts to distinguish itself with an obsessive focus on **usability** and **correctness**. Concurrency is complicated; we try to make it *easy* to get things *right*. Trio was built from the ground up to take advantage of the `latest Python features <https://www.python.org/dev/peps/pep-0492/>`__, and draws inspiration from `many sources <https://github.com/python-trio/trio/wiki/Reading-list>`__, in particular Dave Beazley's `Curio <https://curio.readthedocs.io/>`__. The resulting design is radically simpler than older competitors like `asyncio <https://docs.python.org/3/library/asyncio.html>`__ and `Twisted <https://twistedmatrix.com/>`__, yet just as capable. Trio is the Python I/O library I always wanted; I find it makes building I/O-oriented programs easier, less error-prone, and just plain more fun. `Perhaps you'll find the same <https://github.com/python-trio/trio/wiki/Testimonials>`__. Trio is a mature and well-tested project: the overall design is solid, and the existing features are fully documented and widely used in production. While we occasionally make minor interface adjustments, breaking changes are rare. We encourage you to use Trio with confidence, but if you rely on long-term API stability, consider `subscribing to issue #1 <https://github.com/python-trio/trio/issues/1>`__ for advance notice of any compatibility updates. Where to next? -------------- **I want to try it out!** Awesome! We have a `friendly tutorial <https://trio.readthedocs.io/en/stable/tutorial.html>`__ to get you started; no prior experience with async coding is required. **Ugh, I don't want to read all that – show me some code!** If you're impatient, then here's a `simple concurrency example <https://trio.readthedocs.io/en/stable/tutorial.html#tutorial-example-tasks-intro>`__, an `echo client <https://trio.readthedocs.io/en/stable/tutorial.html#tutorial-echo-client-example>`__, and an `echo server <https://trio.readthedocs.io/en/stable/tutorial.html#tutorial-echo-server-example>`__. **How does Trio make programs easier to read and reason about than competing approaches?** Trio is based on a new way of thinking that we call "structured concurrency". The best theoretical introduction is the article `Notes on structured concurrency, or: Go statement considered harmful <https://vorpus.org/blog/notes-on-structured-concurrency-or-go-statement-considered-harmful/>`__. Or, `check out this talk at PyCon 2018 <https://www.youtube.com/watch?v=oLkfnc_UMcE>`__ to see a demonstration of implementing the "Happy Eyeballs" algorithm in an older library versus Trio. **Cool, but will it work on my system?** Probably! As long as you have some kind of Python 3.10-or-better (CPython or `currently maintained versions of PyPy3 <https://doc.pypy.org/en/latest/faq.html#which-python-versions-does-pypy-implement>`__ are both fine), and are using Linux, macOS, Windows, or FreeBSD, then Trio will work. Other environments might work too, but those are the ones we test on. And all of our dependencies are pure Python, except for CFFI on Windows, which has wheels available, so installation should be easy (no C compiler needed). **I tried it, but it's not working.** Sorry to hear that! You can try asking for help in our `chat room <https://gitter.im/python-trio/general>`_