Files
ruff/crates/ruff_python_formatter
Dylan 924b2972f2 Update Black tests (#22405)
I am updating these because we didn't have test coverage for the
different handling of `fmt: skip` comments applied to multiple
statements on the same line. This is in preparation for #22119 (to show
before/after deviations).

Follows the same procedure as in #20794

Edit: As it happens, the new fixtures do not even cover the case
relevant to #22119 - they just deal with the already handled case of a
one-line compound statement. Nevertheless, it seems worthwhile to make
this update, especially since it uncovered a (possible?) bug.
2026-01-06 09:09:05 -06:00
..
2026-01-06 09:09:05 -06:00
2026-01-02 19:58:15 +00:00

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.