flake8-json

24.4.0 verified Mon Apr 27 auth: no python

Flake8 plugin that formats linting results as JSON. Currently at version 24.4.0, compatible with Python >=3.6. Part of the PyCQA ecosystem. Updates follow Flake8 releases.

pip install flake8-json

Common errors

error ModuleNotFoundError: No module named 'flake8_json' ↓

cause The package 'flake8-json' is not installed or imported incorrectly (hyphen vs underscore).

fix

Install with 'pip install flake8-json' and import as 'import flake8_json' (underscore).

error Flake8 reported no JSON output ↓

cause The --format flag was not set to 'json' or the plugin is not registered.

fix

Run flake8 with --format json. Verify plugin is installed: 'pip list | grep flake8-json'.

error Error: 'format' is not a recognized option ↓

cause Flake8 version is too old to support the --format flag.

fix

Upgrade flake8 to >=3.0.0. flake8-json requires flake8 >=3.0.0.

Warnings

gotcha flake8-json is a formatting reporter; it does not add new lint checks. To get JSON output, use the --format json flag when invoking flake8. ↓

fix Run flake8 with --format json (or configure in setup.cfg).

breaking Versions prior to 24.4.0 may have different behavior for nested violations. Always check the output schema if upgrading from an older version. ↓

fix Upgrade to 24.4.0 and adjust parsing if needed.

deprecated Using 'flake8-json' as a package name (hyphen) is deprecated; import using underscore: 'flake8_json'. ↓

fix Use 'from flake8_json import ...' instead of 'from flake8-json import ...'.

Imports

Flake8JSONFormatter
```
from flake8_json import Flake8JSONFormatter
```
Do not import from 'flake8_json_formatter' or 'flake8_json.Flake8JSONFormatter' if using older versions; the module is 'flake8_json'.

Quickstart

Run flake8 with JSON output format on a file.

import subprocess
result = subprocess.run(['flake8', '--format', 'json', 'myfile.py'], capture_output=True, text=True)
print(result.stdout)