class Stack:
def __init__(self):
self.stack_list = DoublyLinkedList()
@property
def size(self):
return self.stack_list.size
@property
def is_empty(self):
return self.size == 0
def push(self, element):
self.stack_list.add_last(element)
def pop(self):
if self.is_empty:
raise Exception("Empty Stack")
return self.stack_list.remove_last()
def peek(self):
if self.is_empty:
raise Exception("Empty Stack")
return self.stack_list.peek_first()
def __iter__(self):
return DoublyLinkedListIterator(self.stack_list.head)
def test_remove_first_on_one_element_list(self):
""" Should make the list empty """
dll = DoublyLinkedList()
dll.add_last(5)
element = dll.remove_first()
self.assertEqual(element, 5)
self.assertEqual(dll.count, 0)
self.assertEqual(list(dll), [])
def test_add_several_last_elements(self):
dll = DoublyLinkedList()
dll.add_last(5)
dll.add_last(10)
dll.add_last(15)
self.assertEqual(dll.count, 3)
self.assertEqual(list(dll), [5, 10, 15])
def test_remove_first_several_elements(self):
dll = DoublyLinkedList()
dll.add_last(5)
dll.add_last(6)
dll.add_last(7)
first_el = dll.remove_first()
self.assertEqual(first_el, 5)
self.assertEqual(dll.count, 2)
self.assertEqual(list(dll), [6, 7])
def test_cast_to_list_multiple_elements(self):
dll = DoublyLinkedList()
dll.add_last("Five")
dll.add_last("Six")
dll.add_last("Seven")
self.assertEqual(list(dll), ["Five", "Six", "Seven"])
def test_iterate_multiple_elements(self):
dll = DoublyLinkedList()
dll.add_last("Five")
dll.add_last("Six")
dll.add_last("Seven")
items = []
for item in dll:
items.append(item)
self.assertEqual(items, ["Five", "Six", "Seven"])
def test_cast_to_list_one_element(self):
dll = DoublyLinkedList()
dll.add_last(5)
self.assertEqual(list(dll), [5])
def test_add_last_empty_list(self):
dll = DoublyLinkedList()
dll.add_last(5)
self.assertEqual(dll.count, 1)
self.assertEqual(list(dll), [5])