def test_search_for_remove_tail():
"""Test that size works after a remove has occurred on the tail."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(5)
test_dlinked_list.push(7)
test_dlinked_list.push(10)
test_dlinked_list.remove(10)
assert test_dlinked_list.size() == 2
def test_search_for_remove_middle():
"""Test that remove is working."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(5)
test_dlinked_list.push(7)
test_dlinked_list.push(10)
test_dlinked_list.remove(7)
assert test_dlinked_list.size() == 2
class Queue(object):
"""Queue Class which is composed from Linked List."""
def __init__(self):
"""Constructor for Queue."""
self.linked_list = DLinkedList()
def enqueue(self, val):
"""Add new element to end of the queue."""
new_node = Node(self, val)
if self.linked_list.head is None:
self.linked_list.head = new_node
self.linked_list.tail = new_node
else:
self.linked_list.tail.prev_node == new_node
new_node.next_node = self.linked_list.tail
self.linked_list.tail == new_node
def dequeue(self):
"""Remove from the end of the queue."""
if self.linked_list.head is not None:
removed_node = self.linked_list.head
self.linked_list.head.prev_node = self.linked_list.head
return removed_node.data
raise IndexError("List is empty")
def peek(self):
"""Return value of next element in queue."""
return self.linked_list.head
def size(self):
"""Define the size method."""
return self.linked_list.size()
def test_if_shift_needs_no_inputs():
"""Test that an unnecessary parameter will raise a TypeError."""
import pytest
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(5)
test_dlinked_list.push(7)
test_dlinked_list.push(10)
with pytest.raises(TypeError):
test_dlinked_list.shift(5)
def test_output_of_shift_exists():
"""Test that the output exists."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(5)
test_dlinked_list.push(7)
test_dlinked_list.push(10)
assert test_dlinked_list.shift() is not None
def test_search_for_appended_not_found():
"""Test that search doesn't find something that isn't there."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.append(5)
test_dlinked_list.append(7)
test_dlinked_list.append(10)
assert test_dlinked_list.search(11) is None
def test_search_not_found():
"""Test that will search for value not in list."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(5)
test_dlinked_list.push(7)
test_dlinked_list.push(10)
assert test_dlinked_list.search(11) is None
def __init__(self):
"""Constructor for Queue."""
self.linked_list = DLinkedList()
def test_search_for_appended_found():
"""Test that search finds something if it's there."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.append(20)
assert test_dlinked_list.search(20)
def test_search_found():
"""Test that push value to list then search for it."""
from doubly_linked_list import DLinkedList
test_dlinked_list = DLinkedList()
test_dlinked_list.push(20)
assert test_dlinked_list.search(20)
def main():
mylist = DLinkedList()
mylist.append(7)
mylist.push(6)
mylist.push(1)
mylist.append(4)
mylist.insert_after(mylist.get_head().get_next(), 8)
print("Created DLL is:")
mylist.print_list()
print("After the deleting the node")
mylist.delete_node(mylist.get_head().get_next())
mylist.print_list()
print("Reversing a doubly linked list")
reverse_dll(mylist)
mylist.print_list()