If you have enough elements to desire short circuit evaluation you can, as `masklinn` mentioned, use a list comprehension. Specifically a generator list compre

If you have enough elements to desire short circuit evaluation you can, as `masklinn` mentioned, use a list comprehension. Specifically a generator list comprehension. http://www.python.org/dev/peps/pep-0289/ http://www.python.org/dev/peps/pep-0289/ big_list = make_big_list() if any( not prime( a ) for a in big_list ) : do_thing() When you surround the list comprehension syntax with parenthesis instead of square brackets, either as a lone argument to a function or independently, you create a generator that will iterate once over the given data. This allows for functions accepting sequences to short circuit without completing the function mapping.