[Python-Dev] RE: PEP 285: Adding a bool type

[Guido van Rossum]

> Interestingly enough, the exception message says "__nonzero__ should
> return an int" but really means "__nonzero__ must return an int".

You've been staring at standards too much, haven't you?  The
difference between MUST and SHOULD isn't as clear-cut as most
standards people use them.

--Guido van Rossum (home page: http://www.python.org/~guido/)