pycodestyle

Check Python file

$ pycodestyle [script.py]

$ pycodestyle [src/]

$ pycodestyle --show-source [script.py]

$ pycodestyle --show-pep8 [script.py]

$ pycodestyle --ignore=[E501,W503] [script.py]

$ pycodestyle --select=[E1,W1] [script.py]

$ pycodestyle --max-line-length=[120] [script.py]

$ pycodestyle --statistics [src/]

pycodestyle [--ignore codes] [--select codes] [--max-line-length n] [options] files

pycodestyle (formerly pep8) checks Python code against PEP 8 style guidelines. It identifies formatting issues without modifying code.
PEP 8 defines Python's official style: indentation, spacing, naming, and line length conventions. Consistent style improves readability.
Error codes group related issues. E5 codes relate to line length. W503/W504 handle line breaks in expressions. Specific codes can be ignored.
Configuration files (setup.cfg, tox.ini, .pycodestyle) define project-wide settings. These override command-line defaults.
The tool doesn't fix issues automatically. Use autopep8 or black for automatic formatting.
Integration with editors shows issues in real-time. CI pipelines catch style violations before merge.

--ignore CODES

Skip error codes.

Show only error codes.

Line length limit (default 79).

Show source code.

Show PEP8 documentation.

Show error statistics.

Print total errors.

Configuration file.

Show first error only.

Quiet mode.

Time the run.

setup.cfg

Project configuration file with a `[pycodestyle]` section for setting max-line-length, ignore, and select options.

Alternative project configuration file supporting the same `[pycodestyle]` section options.

User-level configuration file for default settings applied when no project config is found.

E1xx

Indentation errors.

Whitespace errors.

Blank line errors.

Import errors.

Line length errors.

Statement errors.

Warnings.

Style checking only - no logical errors. Some rules are debatable (W503 vs W504). Strict line length may not suit all projects.

pycodestyle was originally named pep8, created by Johann C. Rocholl around 2006. It was renamed in 2016 per PEP 8's own advice that Guido's naming conventions are guidelines, not rules.

flake8(1), pylint(1), black(1), autopep8(1)