Linked_List_Deque.py

from Deque import Deque
from Linked_List import Linked_List

class Linked_List_Deque(Deque):

  def __init__(self):
    self.__list = Linked_List()

  def __str__(self):
    return str(self.__list)

  def __len__(self):
    return len(self.__list)

  # DO NOT CHANGE ANYTHING ABOVE THIS LINE

  def push_front(self, val):
    # TODO replace pass with your implementation.
    if len(self) == 0:
        self.__list.append_element(val)
    else:
        self.__list.insert_element_at(val, 0)

  def pop_front(self):
    # TODO replace pass with your implementation.
    if len(self) == 0:
        return 
    return self.__list.remove_element_at(0) 

  def peek_front(self):
    # TODO replace pass with your implementation.
    if len(self) == 0:
        return 
    return self.__list.get_element_at(0)

  def push_back(self, val):
    # TODO replace pass with your implementation.
    self.__list.append_element(val)

  def pop_back(self):
    # TODO replace pass with your implementation.
    if len(self) == 0:
        return 
    return self.__list.remove_element_at(len(self) - 1) 

  def peek_back(self):
    # TODO replace pass with your implementation.
    if len(self) == 0:
        return 
    return self.__list.get_element_at(len(self) - 1)

# Unit tests make the main section unneccessary.
#if __name__ == '__main__':
#    pass