Obviously, map and filter are better because ... ah, hmm, I don't know.

I think it is a matter of language design. Higher order functions are not as prominent in Python as say, Haskell, where map & friends are generally preferred for composability. Lispers prefer map & friends just because list comprehensions add all that messy syntax.

If I were a Python programmer, I would probably use list comprehensions, since they seem to be the preferred idiom.