flake8

Check Python file

$ flake8 [file.py]

$ flake8 [src/]

$ flake8 --select=[E,W] [file.py]

$ flake8 --ignore=[E501] [file.py]

$ flake8 --max-line-length=[120] [file.py]

flake8 [options] [files...]

flake8 is a Python linting tool combining PyFlakes, pycodestyle, and McCabe complexity checker. It finds programming errors, style issues, and overly complex code.
The tool enforces PEP 8 style guidelines and catches common errors like undefined variables, unused imports, and syntax problems. Plugins extend checking for additional frameworks and patterns.
flake8 integrates with editors, CI pipelines, and pre-commit hooks for automated code quality enforcement.

FILES

Python files or directories to check.

Check only specific error codes.

Ignore specific error codes.

Maximum line length (default 79).

Exclude matching files/directories.

Configuration file.

Output format.

Display help information.

setup.cfg

Project-level flake8 configuration in the [flake8] section.

Dedicated flake8 configuration file for project settings.

User-level global configuration file.

Strict defaults may require customization. Some checks overlap with other tools. Plugin ecosystem varies in quality.

flake8 was created by Tarek Ziadé to unify Python linting tools. It wraps multiple checkers under a single interface with consistent configuration and output.

pylint(1), black(1), ruff(1)