pytest-flakes

4.0.5 verified Fri May 01 auth: no python

A pytest plugin that checks Python source code for logical errors using pyflakes. It integrates seamlessly into the pytest ecosystem, automatically running pyflakes on all collected test files and source files. Current version 4.0.5 supports Python >=3.5. The plugin is in maintenance mode; no new features are expected.

pip install pytest-flakes

Common errors

error ModuleNotFoundError: No module named 'pyflakes' ↓

cause Missing dependency pyflakes

fix

pip install pyflakes

error ERROR: usage: pytest [options] [file_or_dir] [file_or_dir] [...] pytest: error: unrecognized arguments: --flakes ↓

cause pytest-flakes is not installed or not activated

fix

pip install pytest-flakes and ensure it's in the test environment

Warnings

gotcha The plugin checks all collected Python files, not just test files. This can cause unexpected failures in third-party code if you have a large source tree. Use --flakes-ignore to exclude files. ↓

fix Configure pytest.ini with flakes-ignore = path/to/ignore*

gotcha Does not work with Python 3.10+? Actually, pyflakes supports up to Python 3.8. But pytest-flakes may still work with newer Python as long as pyflakes parses the code. However, there may be false negatives for newer syntax (match statements, etc.). ↓

fix Consider using flake8 for modern Python syntax support.

Imports

pytest_flakes
wrong
```
from pytest_flakes import ...
```
correct
```
import pytest_flakes
```
Common mistake: users try to import submodules, but the plugin is automatically registered when installed.

Quickstart

Create a test file (e.g., test_demo.py). Run pytest normally. The plugin will automatically check all Python files for pyflakes errors.

import pytest
import sys
sys.path.insert(0, 'src')

def test_ok():
    x = 1
    assert x