(Python docs tend to use "true" to mean anything which isn't "false", and where operator.truth returns the right thing. this won't change post-PEP -- if you start interpreting "return true" as "return True", you'll be asking for trouble)
Unclear. I intend to change as many functions as I reasonably can to return True/False, and I intend to change their documentation to match.
While some of the documentation indeed talks of "true" and "false", those are not well-defined values. They are properties of values, and I find it bad style to say "f() returns true if X and false otherwise". I would have written that either as "f() returns a true value if X and a false value otherwise" (in case I don't want to commit to returning 0 or 1), or "f() returns 1 if X, 0 otherwise" (in case I do).
--Guido van Rossum (home page: http://www.python.org/%7Eguido/)