rules:
  - id: is-not-is-not
    message: >-
      In Python 'X is not ...' is different from 'X is (not ...)'.
      In the latter the 'not' converts the '...' directly to boolean.
    languages: [python]
    severity: ERROR
    pattern: $S is (not ...)
    metadata:
      category: correctness
      technology:
        - python