Linting and Formatting

Local Linting with Flake8 (VSC):

  • Install Flake8 Extension

    • If python environment included flake8 already, it will automatically start linting the python files

    • Otherwise: Install Flake8 (Documentation)

  • Qunicorn Flake8 Settings can be found in .flake8

  • Display the current problems in the console: flake8 .

  • Check for Linting Errors (black & flake) with:

poetry run invoke check-linting

Flake8 Settings

  • Ignore single line: Add # noqa to the end of the line

  • Ignore specific error in a single line: Add # noqa E711 to the end of the line (replace E711 with the error code to suppress)

  • Ignore whole file: Add # flake8: noqa at the start of the file

  • Ignore certain warnings in files, add to .flake8 file

per-file-ignores =
    filename:ErrorCode

e.g.:

per-file-ignores =
    __init__.py:F401,F403,C901

Formatting with black

  • Install Black

pip install black

  • Check if there are open black warnings/errors in the project

black --check .

  • Run Black on a single file:

black filename

  • OR: Run Black on directory or directly on the current navigated folder

black directory/
black .

This will automatically format the selected files

  • Files or directories can also be excluded

black --check --extend-exclude="regex" directory

  • To get more information on the progress add --verbose option

Automatic Formatting on Save

  • In Pycharm:

    • Strg + Alt + A → Search for “Actions on Save” → check “Reformat code” and “Optimize imports”

    • Settings ‣ Editor ‣ Code Style ‣ Python

    • Furthermore: Disable Line breaks reformatting and increase hard wrap