def test_bell_perm():
assert [len(set(generate_bell(i))) for i in range(1, 7)] == [factorial(i) for i in range(1, 7)]
assert list(generate_bell(3)) == [(0, 1, 2), (0, 2, 1), (2, 0, 1), (2, 1, 0), (1, 2, 0), (1, 0, 2)]
# generate_bell and trotterjohnson are advertised to return the same
# permutations; this is not technically necessary so this test could
# be removed
for n in range(1, 5):
p = Permutation(range(n))
b = generate_bell(n)
for bi in b:
assert bi == tuple(p.array_form)
p = p.next_trotterjohnson()
raises(ValueError, lambda: list(generate_bell(0))) # XXX is this consistent with other permutation algorithms?
def test_bell_perm():
assert [len(set(generate_bell(i))) for i in range(1, 7)] == [
factorial(i) for i in range(1, 7)]
assert list(generate_bell(3)) == [
(0, 1, 2), (0, 2, 1), (2, 0, 1), (2, 1, 0), (1, 2, 0), (1, 0, 2)]
# generate_bell and trotterjohnson are advertised to return the same
# permutations; this is not technically necessary so this test could
# be removed
for n in range(1, 5):
p = Permutation(range(n))
b = generate_bell(n)
for bi in b:
assert bi == tuple(p.array_form)
p = p.next_trotterjohnson()
raises(ValueError, lambda: list(generate_bell(0))) # XXX is this consistent with other permutation algorithms?
