unreasonably effective

you can be sloppy, as long as you are rigorous

Python: Assertions

Execution of assert‘s is controlled by __debug__ variable. In optimized mode (-o or -oo), __debug__ is False, so assert‘s are no-op.

Best practice:

DON’T use assert for code that must be executed for program correctness like checking user inputs.
DO use assert on invariants.
DO use assert to check inputs coming from other parts of a program.

tanvirdotzaman