c5b58187da
Closes #18671 Note that while this has, I believe, always been invalid syntax, it was reported as a different syntax error until Python 3.12: Python 3.11: ```pycon >>> x = 1 >>> f"{x! s}" File "<stdin>", line 1 f"{x! s}" ^ SyntaxError: f-string: invalid conversion character: expected 's', 'r', or 'a' ``` Python 3.12: ```pycon >>> x = 1 >>> f"{x! s}" File "<stdin>", line 1 f"{x! s}" ^^^ SyntaxError: f-string: conversion type must come right after the exclamanation mark ```
Ruff Formatter
The Ruff formatter is an extremely fast Python code formatter that ships as part of the ruff
CLI.
Goals
The formatter is designed to be a drop-in replacement for Black, but with an excessive focus on performance and direct integration with Ruff.
Specifically, the formatter is intended to emit near-identical output when run over Black-formatted code. When run over extensive Black-formatted projects like Django and Zulip, > 99.9% of lines are formatted identically. When migrating an existing project from Black to Ruff, you should expect to see a few differences on the margins, but the vast majority of your code should be unchanged.
If you identify deviations in your project, spot-check them against the intentional deviations enumerated below, as well as the unintentional deviations filed in the issue tracker. If you've identified a new deviation, please file an issue.
When run over non-Black-formatted code, the formatter makes some different decisions than Black, and so more deviations should be expected, especially around the treatment of end-of-line comments. For details, see Style Guide.
Getting started
Head to The Ruff Formatter for usage instructions and a comparison to Black.