def test_negative_index(self):
iterable = 'abcde'
r = 4
n = factorial(len(iterable)) // factorial(len(iterable) - r)
for index, expected in enumerate(permutations(iterable, r)):
actual = mi.nth_permutation(iterable, r, index - n)
self.assertEqual(actual, expected)
def test_long(self):
iterable = tuple(range(180))
r = 4
index = 1000000
actual = mi.nth_permutation(iterable, r, index)
expected = mi.nth(permutations(iterable, r), index)
self.assertEqual(actual, expected)
def test_null(self):
actual = mi.nth_permutation([], 0, 0)
expected = tuple()
self.assertEqual(actual, expected)
def test_r_equal_to_n(self):
iterable = 'abcde'
for index, expected in enumerate(permutations(iterable)):
actual = mi.nth_permutation(iterable, None, index)
self.assertEqual(actual, expected)
def test_r_less_than_n(self):
iterable = 'abcde'
r = 4
for index, expected in enumerate(permutations(iterable, r)):
actual = mi.nth_permutation(iterable, r, index)
self.assertEqual(actual, expected)
def _create_permutation(self, feed, index=0):
permutation = nth_permutation(feed, r=self.length, index=index)
username = "".join(permutation).lower()
return username