Pylint Guide

Overview

This guide illustrates how to modify the .pylintrc file to enable lint exclusions in your repo, eliminating the need to create a Help Desk ticket to add exclusions to your product YAML configuration.

Configuration

The following .pylintrc is an example from the python-world project .

[DESIGN]

[TYPECHECK]

[MASTER]
ignore=tests
disable=missing-function-docstring,
     missing-class-docstring,
     invalid-name

[MESSAGES CONTROL]

[FORMAT]
max-line-length=100

Under the MASTER section of the .pylintrc file, add "ignore=path/file". In the example above, any directories that contain .cache/ and python_packages/ will be excluded from the pylint job.

Reference

• Regex cheat sheet
• Pylintrc configuration page

Generating .pylintrc

# To generate a .pylintrc file, run the following command
pylint --generate-rcfile # This will place the .pylintrc file in the current directory
pylint --generate-rcfile > directory/path/of/your/choice # This will place the .pylintrc file in the directory of your choosing

NOTE

Additional switches must be placed in front of --generate-rcfile.

# This is an example pylint generation
pylint --ignore=^.*\/cache\/ --generate-rcfile

Examples

1. This example loosens Pylint’s strictness by ignoring certain folders, disabling docstring and naming warnings, and allowing lines up to 100 characters.

   [DESIGN]
   
   [TYPECHECK]
   
   [MASTER]
   ignore-paths=^.*\.cache\/.*$,
               ^.*python_packages\/.*$
   disable=missing-function-docstring,
         missing-class-docstring,
         invalid-name
   
   [MESSAGES CONTROL]
   
   [FORMAT]
   max-line-length=100

2. This example configures Pylint to fail on errors, require a minimum score, allow certain short variable names, ignore docstring warnings, and use Django settings for string-based foreign keys.

   [MASTER]
   
   fail-on=E
   fail-under=7.0
   load-plugins=pylint_django
   py-version=3.8
   
   [MESSAGES CONTROL]
   
   disable=missing-module-docstring,
         missing-class-docstring,
         missing-function-docstring
   
   [REPORTS]
   
   output-format=colorized
   reports=no
   score=yes
   
   [BASIC]
   
   good-names=i,
            j,
            k,
            ex,
            obj,
            Run,
            _
   
   [DJANGO FOREIGN KEYS REFERENCED BY STRINGS]
   
   django-settings-module=scala_alocacao.settings

Troubleshooting

Missing init.py error

__init__.py:1:0: F0010: error while code parsing: Unable to load file /builds/platform-one/products/widow/widow-python/__init__.py:
[Errno 2] No such file or directory: '/builds/platform-one/products/widow/widow-python/__init__.py' (parse-error)
ERROR: Job failed: command terminated with exit code 1

The current pipeline job runs pylint $(pwd). This is a folder-based scan. Pylint will consider this type a package-based scan. The package-based scan expects init.py files.

• Review this article on Folder analysis fails if 'init.py' is not present.

• If your team cannot add the init.py files, submit a Pipeline Issue ticket with the Help Desk and request the use of a pylint file-based scan.

References

• Review the official pylint FAQ