Python Formatter

The formatter applies its engine rules and configurable options. The separate basic checker covers approximate E501, W291, E101, E111 and E302 checks; it does not certify complete PEP 8 compliance.

Use the basic check after successful syntax parsing. It reports the covered whitespace, indentation, line-length and blank-line checks. A passing result says nothing about untested rules.

Yes, the formatter is specifically designed for Python's indentation-sensitive syntax, correctly handling nested blocks, continuation lines, and multi-line expressions while preserving logical structure.

The formatter supports Python 3.x syntax including f-strings, walrus operator, match/case statements, type hints, dataclasses, and other modern Python features.

The syntax parser runs before any formatting, so code that does not parse is never rewritten. The error message is displayed with the affected line and your input is left unchanged. Fix the reported error and run the format action again.

The separate basic check uses 79 characters for its line-length warning. Formatting has its own configured line width; these settings are separate. This page does not certify PEP 257 compliance.

Python indentation is part of its syntax. The Ruff formatter parses the input and reports syntax errors before formatting. Review the output; formatting is not proof of behavioral equivalence or complete PEP 8 compliance.

f-string replacement fields {expr!r:>10} are preserved exactly - their contents are expressions the formatter does not rewrite. Type hints (PEP 484) get standard spacing around colons (def f(x: int) -> str:) and modern union syntax (int | None) is left as written, since it is valid from Python 3.10.