flake8-file-length 0.1.0

Flake8 plugin to enforce a maximum number of lines per file

flake8-file-length (FLN)

A Flake8 plugin that enforces a maximum number of lines per file.

• Plugin name: flake8-file-length
• Version: 0.1.0
• Error code prefix: FLN
• Primary rule: FLN001 file too long: {count} lines (limit {limit}){suffix}
  • When any ignore option is active, the message includes a suffix with total and effective counts: — total=…, effective=….

Installation

pip install flake8-file-length

Check flake8 version to ensure the plugin is registered:

flake8 --version
7.3.0 (flake8-file-length: 0.1.0, mccabe: 0.7.0, pycodestyle: 2.14.0, pyflakes: 3.4.0) CPython 3.13.7 on Linux

Quick start

Run Flake8 selecting only this plugin on your source tree:

flake8 --select FLN path/to/code

By default, files longer than 400 lines will trigger FLN001.

Configuration

You can configure the plugin via any Flake8-supported config file (.flake8, setup.cfg, tox.ini, or pyproject.toml under the [tool.flake8] table). Options:

• --max-file-length INT (default 400)
• --file-length-ignore-blank (bool; default false)
• --file-length-ignore-comments (bool; default false)
• --file-length-ignore-shebang (bool; default true)

Example .flake8:

[flake8]
select = FLN
max-file-length = 120
file-length-ignore-blank = true
file-length-ignore-comments = true
file-length-ignore-shebang = true

Precommit hook example

To use with pre-commit, add to your .pre-commit-config.yaml:

  - repo: https://github.com/pycqa/flake8
    rev: 7.3.0
    hooks:
      - id: flake8
        additional_dependencies:
          - flake8-file-length==0.1.0 
        args:
          - --select=FLN                 
          - --max-file-length=300
          - --file-length-ignore-blank
          - --file-length-ignore-comments
          - --file-length-ignore-shebang