def test_deque_try_multiple_things():
deque = Deque()
deque.append_left(0)
deque.append_left(1)
# [1, 0]
deque.append_right(3)
deque.append_right(4)
# [1, 0, 3, 4]
item1 = deque.pop_left()
item2 = deque.pop_right()
assert item1 == 1
assert item2 == 4
item3 = deque.pop_right()
item4 = deque.pop_right()
assert item3 == 3
assert item4 == 0
assert deque.is_empty() is True
with pytest.raises(IndexError):
deque.pop_left()
with pytest.raises(IndexError):
deque.pop_right()
def test_deque_pop_left():
deque = Deque()
deque.append_left(0)
deque.append_left(1)
item = deque.pop_left()
assert item == 1
assert deque.size() == 1
def test_deque_pop_right():
deque = Deque()
deque.append_left(0)
deque.append_left(1)
item = deque.pop_right()
item2 = deque.pop_right()
assert item == 0
assert item2 == 1
assert deque.is_empty() is True
def test_deque_append_right_pop_left():
deque = Deque()
deque.append_right(0)
deque.append_right(1)
item0 = deque.pop_left()
item1 = deque.pop_left()
assert item0 == 0
assert item1 == 1
assert deque.is_empty() is True
def test_deque_pop_left_multiple():
deque = Deque()
deque.append_left(0)
deque.append_left(1)
item1 = deque.pop_left()
item2 = deque.pop_left()
assert item1 == 1
assert item2 == 0
assert deque.is_empty() is True
def test_deque_pop_left_empty():
deque = Deque()
with pytest.raises(IndexError):
deque.pop_left()
def test_create_empty_deque():
deque = Deque()
assert deque.head is None
assert deque.tail is None
def test_deque_append_right():
deque = Deque()
deque.append_right(0)
deque.append_right(1)
assert deque.size() == 2