OK so let's talk about that, which is more readable?:

  iterable = xrange(10)

  ge = (x*x for x in iterable if not x % 2)

  mf = map(lambda x: x*x, filter(lambda x: not x % 2, iterable))

Assume imap and ifilter from itertools or Python 3 (with range) for equivalence. I'm betting if we ask any person new to Python and new to programming, they'd think the former much more readable than the latter. Yes, we left it in the language for you cranks who think map, filter, and lambda are way better, but it's functionally no different.