flake8: Python Linter

Flake8 is a Python linting tool that enforces style consistency and checks for programming errors. It combines multiple code quality tools into a single interface: PyFlakes for logical errors, pycodestyle for style checking, and mccabe for code complexity checking.

Key Features

Code Analysis

• Detects undefined variables and imports
• Identifies unused imports and variables
• Finds syntax errors and questionable coding patterns
• Measures cyclomatic complexity

Style Enforcement

• Validates PEP 8 compliance
• Checks line length limits
• Enforces whitespace rules
• Verifies import ordering

Configuration Support

• Per-project settings via setup.cfg, tox.ini, or .flake8
• Line-level error suppression with # noqa
• Granular rule enabling/disabling
• Custom maximum line length

Usage

Basic command line usage:

# Install with uv
uv pip install flake8

# Run flake8
flake8 path/to/code/

Limitations

• No auto-fix capabilities
• Slower performance compared ruff
• Limited type checking support
• No formatting capabilities

Learn More

• Flake8 Documentation
• Configuration Guide