μsort (usort) is a Python import sorting utility designed to make minimal, predictable changes to source code. Its primary objective is to organise imports without introducing potentially unsafe transformations or unnecessarily altering existing formatting.
Unlike import sorters that may reorganise entire import sections, μsort identifies blocks of statements that can be safely reordered. Imports separated by executable statements or certain comments are treated as independent blocks, reducing the possibility of changing program behaviour.
The utility is particularly suitable for projects where preserving source layout and avoiding unnecessary changes are important. It is designed to work alongside general-purpose code formatters and linters rather than replace them.
μsort provides command-line operations for formatting imports, checking their order and reviewing proposed changes.
This is free and open source software.
Key Features
- Automatically sorts Python imports using a safety-first approach.
- Identifies independent blocks of imports that can be safely reordered.
- Avoids moving imports across executable statements and other block boundaries.
- Groups imports into standard library, third-party, first-party and relative categories.
- Sorts imports lexicographically within their respective groups.
- Preserves existing formatting wherever possible rather than rewriting import layouts.
- Supports sorting imports in individual source files and directories.
- Provides a format command to apply import ordering changes.
- Offers diff mode for reviewing proposed changes without modifying files.
- Includes check mode for validating import order in automated workflows.
- Recognises #usort:skip directives for excluding specific imports from sorting.
- Supports #isort:skip directives for compatibility with existing projects.
- Allows configuration of import categories and sorting behaviour.
- Integrates with pre-commit for automatic import checking and organisation.
- Works alongside other Python code formatting and linting tools.
Website: github.com/facebook/usort
Support:
Developer: Meta
License: MIT License
usort is written in Python. Learn Python with our recommended free books and free tutorials.
Related Software
| Python Code Formatters | |
|---|---|
| Ruff | Extremely fast Python linter and code formatter |
| YAPF | Python formatter based on clang-format |
| Black | Uncompromising Python code formatter |
| isort | Python utility and library to sort imports |
| autopep8 | Formats Python code to conform to the PEP 8 style guide |
| Darker | Apply black reformatting to Python files |
| Pyink | Python code formatter |
| blue | Somewhat less uncompromising code formatter than black |
| μsort | Sorts import statements |
| eradicate | Remove commented-out code from Python files |
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