8b9ab48ac6
Summary -- Fixes #20844 by refining the unsupported syntax error check for [PEP 701] f-strings before Python 3.12 to allow backslash escapes and escaped outer quotes in the format spec part of f-strings. These are only disallowed within the f-string expression part on earlier versions. Using the examples from the PR: ```pycon >>> f"{1:\x64}" '1' >>> f"{1:\"d\"}" Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: Invalid format specifier '"d"' for object of type 'int' ``` Note that the second case is a runtime error, but this is actually avoidable if you override `__format__`, so despite being pretty weird, this could actually be a valid use case. ```pycon >>> class C: ... def __format__(*args, **kwargs): return "<C>" ... >>> f"{C():\"d\"}" '<C>' ``` At first I thought narrowing the range we check to exclude the format spec would only work for escapes, but it turns out that cases like `f"{1:""}"` are already covered by an existing `ParseError`, so we can just narrow the range of both our escape and quote checks. Our comment check also seems to be working correctly because it's based on the actual tokens. A case like [this](https://play.ruff.rs/9f1c2ff2-cd8e-4ad7-9f40-56c0a524209f): ```python f"""{1:# }""" ``` doesn't include a comment token, instead the `#` is part of an `InterpolatedStringLiteralElement`. Test Plan -- New inline parser tests [PEP 701]: https://peps.python.org/pep-0701/ |
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| resources/test/fixtures | ||
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| Cargo.toml | ||
| CONTRIBUTING.md | ||
| generate.py | ||
| orphan_rules_in_the_formatter.svg | ||
| README.md | ||
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.