Python's [] at least 3x faster than list()?

Question

It appears that using [] around a generator expression (test1) behaves substantially better than putting it inside of list() (test2). The slowdown isn\'t there when I simpl

Answer 1

Your test2 is roughly equivalent to:

def test2():
    def local():
        for i in x:
            yield i
    return list(local())

The call overhead explains the increased processing time.