CodeQL documentation

First parameter of a method is not named ‘self’

ID: py/not-named-self
Kind: problem
Severity: recommendation
Precision: very-high
Tags:
   - maintainability
   - readability
   - convention
Query suites:
   - python-security-and-quality.qls

Click to see the query in the CodeQL repository

Normal methods should have at least one parameter and the first parameter should be called self. This makes the purpose of the parameter clear to other developers.

Recommendation

If there is at least one parameter, then change the name of the first parameter to self as recommended by the style guidelines in PEP 8.

If there are no parameters, then it cannot be a normal method. It may need to be marked as a staticmethod or it could be moved out of the class as a normal function.

Example

The following methods can both be used to assign values to variables in a point object. The second method makes the association clearer because the self parameter is used.

class Point:
    def __init__(val, x, y):  # first parameter is mis-named 'val'
        val._x = x
        val._y = y

class Point2:
    def __init__(self, x, y):  # first parameter is correctly named 'self'
        self._x = x
        self._y = y

References