class Queue():
"""implementing queue functionality from LL"""
def __init__(self, data):
"""init"""
self.linked_list = LL(LLN(data))
def __str__(self):
"""tostring method"""
return str(self.linked_list).replace('Linked List', 'Queue')
def enqueue(self, new_value):
"""enqueuing stuff onto list (onto top of LL))"""
self.linked_list.insert(new_value)
def dequeue(self):
"""takes the last thing off of the list"""
curr = self.linked_list.head
prev = None
while curr.get_next():
prev = curr
curr = curr.get_next()
if prev:
prev.update_next(None)
return curr
else:
raise ValueError("Cant remove last element of queue")
class Stack():
"""implementing stack functionality as a linked list"""
def __init__(self, data):
"""initialization"""
self.linked_list = LL(LLN(data))
def __str__(self):
"""tostring method"""
return str(self.linked_list).replace('Linked List', 'Stack')
def peek(self):
"""get top of stack"""
return self.linked_list.head
def pop(self):
"""popping off the last value (first value in LL)"""
node = self.linked_list.head
self.linked_list.head = self.linked_list.head.get_next()
return node
def push(self, new_value):
"""pushing stuff onto list (onto top of LL))"""
self.linked_list.insert(new_value)
class TestLinkedList(unittest.TestCase):
def setUp(self):
self.list = LL()
def tearDown(self):
self.list = None
def test_insert(self):
self.list.insert("David")
self.assertTrue(self.list.head.get_data() == "David")
self.assertTrue(self.list.head.get_next() is None)
def test_insert_two(self):
self.list.insert("David")
self.list.insert("Thomas")
self.assertTrue(self.list.head.get_data() == "Thomas")
head_next = self.list.head.get_next()
self.assertTrue(head_next.get_data() == "David")
def test_nextNode(self):
self.list.insert("Jacob")
self.list.insert("Pallymay")
self.list.insert("Rasmus")
self.assertTrue(self.list.head.get_data() == "Rasmus")
head_next = self.list.head.get_next()
self.assertTrue(head_next.get_data() == "Pallymay")
last = head_next.get_next()
self.assertTrue(last.get_data() == "Jacob")
def test_positive_search(self):
self.list.insert("Jacob")
self.list.insert("Pallymay")
self.list.insert("Rasmus")
found = self.list.search("Jacob")
self.assertTrue(found.get_data() == "Jacob")
found = self.list.search("Pallymay")
self.assertTrue(found.get_data() == "Pallymay")
found = self.list.search("Jacob")
self.assertTrue(found.get_data() == "Jacob")
def test_searchNone(self):
self.list.insert("Jacob")
self.list.insert("Pallymay")
# make sure reg search works
found = self.list.search("Jacob")
self.assertTrue(found.get_data() == "Jacob")
with self.assertRaises(ValueError):
self.list.search("Vincent")
def test_delete(self):
self.list.insert("Jacob")
self.list.insert("Pallymay")
self.list.insert("Rasmus")
# Delete the list head
self.list.delete("Rasmus")
self.assertTrue(self.list.head.get_data() == "Pallymay")
# Delete the list tail
self.list.delete("Jacob")
self.assertTrue(self.list.head.get_next() is None)
def test_delete_value_not_in_list(self):
self.list.insert("Jacob")
self.list.insert("Pallymay")
self.list.insert("Rasmus")
with self.assertRaises(ValueError):
self.list.delete("Sunny")
def test_delete_empty_list(self):
with self.assertRaises(ValueError):
self.list.delete("Sunny")
def test_delete_next_reassignment(self):
self.list.insert("Jacob")
self.list.insert("Cid")
self.list.insert("Pallymay")
self.list.insert("Rasmus")
self.list.delete("Pallymay")
self.list.delete("Cid")
self.assertTrue(self.list.head.next_node.get_data() == "Jacob")