check-comma-in-class-attributes

Pre-commit hook to check if has a comma in any class attribute.

But why it matters?

# main.py

class Person:
    def __init__(self, name: str, age: int) -> None:
        self.name = name,
        self.age = age

    def greet(self) -> None:
        print(f"Hi, my name is {self.name} and I'm {self.age} years old!")

person_1 = Person(name='Marcos', age=25)
person_1.greet()

If you execute the main.py you got:

Hi, my name is ('Marcos',) and I'm 25 years old!

Instead of:

Hi, my name is Marcos and I'm 25 years old!

It's important to emphasize that is not necessarily a syntax error, and it's not even identified by linters by default, but it will produce unexpected behavior when retrieving the value of the self.name attribute.

Usage

It's only possible to use this hook with pre-commit, so put this inside your .pre-commit-config.yaml:

- repo: https://github.com/marcosdotme/check-comma-in-class-attributes
  rev: 0.1.0
  hooks:
    - id: check-comma-in-class-attributes

Demo output