flake8-functions
A flake8 extension that checks functions
Decision gist · record as of 2026-08-14
Yes, if your team values function-level code quality enforcement and uses flake8. The plugin is lightweight, actively maintained, carries no licensing restrictions, and has no external dependencies. Install it if you want automated checks for function complexity; skip it if your team prefers manual review or uses a different linter.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later; flake8 must be installed and configured.
- Low friction install with no runtime dependencies.
- Active maintenance as of 2026-08-14 with recent release history since 2019.
License · maintenance · safety
MIT (permissive) — MIT license permits commercial and private use with minimal restrictions; suitable for most projects.
last release 2026-08-14 (0 days) · last repo commit 2026-08-14 · 50 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 356,801 downloads/mo, #7,278 on PyPI
Alternatives
Verify before relying
pip install flake8-functions
flake8 --max-function-length=100 your_code.py- Whether CFQ003 (purity check) correctly identifies side effects in all Python patterns
- How configurable thresholds interact with existing flake8 configuration files
- Performance impact on large codebases with many functions
What it is and what it does
flake8-functions is a linter plugin that adds four new rule categories to flake8, targeting functions that may harm code readability or maintainability. It checks for functions exceeding a configurable line length (CFQ001, default 100), functions with too many parameters (CFQ002, default 6), functions that are not pure (CFQ003), and functions with excessive return statements (CFQ004, default 3). The tool integrates directly into flake8's reporting pipeline, so violations appear alongside standard flake8 output.
The package is designed for teams where code readability across multiple developers is a priority. It has no runtime dependencies beyond flake8 itself, installs cleanly, and supports Python 3.10 through 3.14. Configuration is done via flake8's standard command-line flags (e.g., --max-function-length). The project is actively maintained and carries an MIT license.
Use it for
- Enforce maximum function length in team codebases to prevent functions spanning multiple screens
- Limit function parameter counts to catch overly complex function signatures during code review
- Detect functions with multiple return statements that may indicate unclear control flow
- Identify impure functions (those with side effects) in codebases targeting functional programming patterns
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if your team values function-level code quality enforcement and uses flake8.
The plugin is lightweight, actively maintained, carries no licensing restrictions, and has no external dependencies. Install it if you want automated checks for function complexity; skip it if your team prefers manual review or uses a different linter.
Install
flake8-functions on PyPI
Before you install
Low friction install with no runtime dependencies. Active maintenance as of 2026-08-14 with recent release history since 2019.
Requires Python 3.10 or later; flake8 must be installed and configured.
License in practice
MIT license permits commercial and private use with minimal restrictions; suitable for most projects.
Quickstart
pip install flake8-functions
flake8 --max-function-length=100 your_code.pyVerify before relying
- Whether CFQ003 (purity check) correctly identifies side effects in all Python patterns
- How configurable thresholds interact with existing flake8 configuration files
- Performance impact on large codebases with many functions
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 0 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 356,801 / month, #7,278 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Environment :: ConsoleFramework :: Flake8Intended Audience :: DevelopersOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Topic :: Software Development :: DocumentationTopic :: Software Development :: Libraries :: Python ModulesTopic :: Software Development :: Quality AssuranceTyping :: Typed |
Evidence: flake8_functions-0.1.0-py3-none-any.whl
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