def test_permutations_k_equals_2(self):
"""permutations should return n*(n-1) if k=2"""
for n in self.standards[2:]:
self.assertEqual(permutations(n,2), n*(n-1))
def test_permutations_k_equals_n(self):
"""permutations should return n! if k=n"""
for n in self.standards[1:]:
self.assertEqual(permutations(n,n), reduce(mul, range(1,n+1)))
def test_permutations_k_equals_1(self):
"""permutations should return n if k=1"""
for n in self.standards[1:]:
self.assertEqual(permutations(n,1), n)