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Regular Expression Linter

Write your own linting rules using regular expressions.

PyPi Version Test Coverage GitHub License


python3 -m pip install relint

Examples & Recipes – The reLint Cookbook


You can write your own regular rules in a YAML file, like so:

- name: No ToDo
  pattern: '(?i)todo' # case insensitive flag
  hint: Get it done right away!
  filePattern: .*\.(py|js)
  error: false

The name attribute is the name of your linter, the pattern can be any regular expression. The linter does lint entire files, therefore your expressions can match multiple lines and include newlines.

You can narrow down the file types your linter should be working with, by providing the optional filePattern attribute. The default is .*.

The optional error attribute allows you to only show a warning but not exit with a bad (non-zero) exit code. The default is true.

The following command will lint all files in the current directory:

relint -c .relint.yml **

The default configuration file name is .relint.yml within your working directory, but you can provide any YAML or JSON file.

If you prefer linting changed files (cached on git) you can use the option --diff [-d] or --git-diff [-g]:

git diff --unified=0 | relint --diff


You can automate the linting process by adding a pre-commit hook to your project. Add the following entry to your .pre-commit-config.yaml:

- repo:
  rev: 1.4.0
    - id: relint
      args: [-W]  # optional, if you want to fail on warnings during commit