def test_dllist_complicated_case(self):
ll3 = DLList(13)
ll3.push(14)
ll3.shift(12)
ll3.push(15)
assert ll3.unshift() == 12
assert ll3.pop() == 15
assert ll3.unshift() == 13
assert ll3.pop() == 14
with pytest.raises(Exception):
ll3.pop()
def test_dllist_len(self):
ll = DLList((1, 2))
assert len(ll) == 1
ll.shift((2, 3))
assert len(ll) == 2
ll.push((3, 4))
assert len(ll) == 3
ll.pop()
assert len(ll) == 2
ll.unshift()
assert len(ll) == 1
ll.pop()
assert len(ll) == 0