2. Boolean Operations — and, or, not

These are the Boolean operations, ordered by ascending priority:

Operation Result Notes
x or y if x is false, then y, else x (1)
x and y if x is false, then x, else y (2)
not x if x is false, then True, else False (3)

Notes:

  1. This is a short-circuit operator, so it only evaluates the second argument if the first one is False.
  2. This is a short-circuit operator, so it only evaluates the second argument if the first one is True.
  3. not has a lower priority than non-Boolean operators, so not a == b is interpreted as not (a == b), and a == not b is a syntax error.