test_util.py 文件源码

def test_perm(self):
        ''' Permutations. '''
        fs_ord = set()
        fs_unord = set()
        for fs in util.factorize(512, 3):
            fs_ord.add(fs)
            fs_unord.add(frozenset(fs))

        cnt = 0
        for fs in fs_unord:
            if len(fs) == 3:
                # Permutations.
                cnt += math.factorial(3)
            elif len(fs) == 2:
                # Permutations of a, a, b.
                cnt += 3
            else:
                # Pattern a, a, a.
                cnt += 1
        self.assertEqual(len(fs_ord), cnt)