NonSelf.ql

/**
 * @name First parameter of a method is not named 'self'
 * @description Using an alternative name for the first parameter of an instance method makes
 *              code more difficult to read; PEP8 states that the first parameter to instance
 *              methods should be 'self'.
 * @kind problem
 * @tags maintainability
 *       readability
 *       convention
 * @problem.severity recommendation
 * @sub-severity high
 * @precision very-high
 * @id py/not-named-self
 */

import python
import MethodArgNames

from Function f, string message
where
  firstArgShouldBeNamedSelfAndIsnt(f) and
  (
    (
      if exists(f.getArgName(0))
      then
        message =
          "Normal methods should have 'self', rather than '" + f.getArgName(0) +
            "', as their first parameter."
      else
        message =
          "Normal methods should have at least one parameter (the first of which should be 'self')."
    ) and
  ) 
select f, message