ruff/crates/ruff_python_parser
Dylan c5b58187da
Add syntax error when conversion flag does not immediately follow exclamation mark (#18706)
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
```
2025-06-16 11:44:42 -05:00
..
resources Add syntax error when conversion flag does not immediately follow exclamation mark (#18706) 2025-06-16 11:44:42 -05:00
src Add syntax error when conversion flag does not immediately follow exclamation mark (#18706) 2025-06-16 11:44:42 -05:00
tests Add syntax error when conversion flag does not immediately follow exclamation mark (#18706) 2025-06-16 11:44:42 -05:00
Cargo.toml Allow passing ParseOptions to inline tests (#16357) 2025-02-27 10:23:15 -05:00
CONTRIBUTING.md Update pre-commit dependencies (#17073) 2025-03-31 07:42:15 +00:00
README.md Add basic docs for the parser crate (#11199) 2024-04-29 17:08:07 +00:00

Ruff Python Parser

Ruff's Python parser is a hand-written recursive descent parser which can parse Python source code into an Abstract Syntax Tree (AST). It also utilizes the Pratt parsing technique to parse expressions with different precedence.

Try out the parser in the playground.

Python version support

The parser supports the latest Python syntax, which is currently Python 3.12. It does not throw syntax errors if it encounters a syntax feature that is not supported by the target-version. This will be fixed in a future release (see https://github.com/astral-sh/ruff/issues/6591).

Contributing

Refer to the contributing guidelines to get started and GitHub issues with the parser label for issues that need help.