Code in python please without the use of import

Create a function called create_room that takes four parameters; a doubly linked list containing surnames, a string representing room name and number, an int representing the capacity of the room and an int representing the index of the node that contains the surname of the first person that is assigned to this room. Your job is to return a string that shows the two first letters of the surnames of the first and last person that should attend the given room. Here is an example: >>> create_room(list1, Room69, 80, 150) Room69 JU-MO

Below I have attached the code for the double linked list :

class DNode(): '''represents a node as a building block of a double linked list'''   def __init__(self, element, prev_node=None, next_node=None): '''(Node, obj, Node, Node) -> NoneType  construct a Dnode as building block of a double linked list'''  # Representation invariant: # element is an object, that is hold this node # _prev is a DNode # _next is a DNode # _prev is the node immediately before this node (i.e. self) # _next is the node immediately after this node (i.e. self) self._element = element self._next = next_node self._prev = prev_node def set_next(self, next_node): '''(Node, Node) -> NoneType  set node to point to next_node'''  self._next = next_node def set_prev(self, prev_node): '''(Node, Node) -> NoneType  set node to point to prev_node'''  self._prev = prev_node def set_element(self, element): '''(Node, obj) ->NoneType  set the _element to a new value'''  self._element = element def get_next(self): '''(Node) -> Node  returns the reference to next node'''  return self._next def get_prev(self): '''(Node) -> Node  returns the reference to previous node'''  return self._prev def get_element(self): '''(Node) -> obj  returns the element of this node'''  return self._element def __str__(self): '''(Node) -> str  returns the element of this node and the reference to next node'''  return "(" + str(hex(id(self._prev))) + ", " + str(self._element) + ", " + str(hex(id(self._next))) + ")" class DoubleLinkedList(): ''' represents a double linked list'''   def __init__(self): '''(DoubleLinkedList) ->NoneType  initializes the references of an empty DLL'''  # set the size self._size = 0 # head and tails are a dummy node self._head = DNode(None, None, None) self._tail = DNode(None, None, None) # head points to tail and tail to head self._head.set_next(self._tail) self._tail.set_prev(self._head) def is_empty(self): '''(DoubleLinkedList) -> bool  returns true if no item is in this DLL'''  return self._size == 0 def size(self): '''(DoubleLinkedList) -> int  returns the number of items in this DLL'''  return self._size def get_first(self): '''(DoubleLinkedList) -> Dnode  return a pointer to the first node in the list if the list is not empty,  otherwise the pointer points to the (dummy) tail'''  return self._head.get_next() def get_last(self): '''(DoubleLinkedList) -> Dnode  return a pointer to the last node in the list if the list is not empty,  otherwise the pointer points to the (dummy) head'''  return self._tail.get_prev() def add_first(self, element): '''(DoubleLinkedList, obj) -> NoneType  adds a node to the front of the DLL, after the head'''  # create a node that head points to. Also the node points to the node after the head node = DNode(element, self._head, self._head.get_next()) # have the node after head to point to this node (_prev) self._head.get_next().set_prev(node) # have the head to point to this new node self._head.set_next(node) # increment the size self._size += 1 def add_last(self, element): '''(DoubleLinkedList, obj) -> NoneType  adds a node to the end of this DLL'''  # create a DNode with the given element that points to tail from right and to the node before the tail from left node = DNode(element, self._tail.get_prev(), self._tail) # let the node to the left of the tail to point to this new node self._tail.get_prev().set_next(node) # let the _prev part of the tail to point to newly created node self._tail.set_prev(node) # increment the size self._size += 1 def remove_first(self): '''(DoubleLinkedList, obj) -> obj  remvoe the node from the head of this DLL and returns the element stored in this node'''  # set element to None in case DLL was empty element = None # if DLL is not empty if (not self.is_empty()): # get the first node to the right of the head node = self._head.get_next() # have head point to the second node after the head self._head.set_next(node.get_next()) # have the second node after the head to point to head from left node.get_next().set_prev(self._head) # decrement the size self._size -= 1 # set the _next & _prev of the removed node to point to None (for garbage collection purpose) node.set_next(None) node.set_prev(None) # get the element stored in the node element = node.get_element() # return the element of the removed node return element def remove_last(self): '''(DoubleLinkedList, obj) -> obj  remvoe the node from the tail of this DLL and returns the element stored in this node'''  # set element to None in case DLL was empty element = None # if DLL is not empty if (not self.is_empty()): # get the first node to the left of the tail node = self._tail.get_prev() # have tail point to the second node before the tail self._tail.set_prev(node.get_prev()) # have the second node before the tail to point to tail from right node.get_prev().set_next(self._tail) # decrement the size self._size -= 1 # get the element stored in the node element = node.get_element() # Nullify the deleted node (for garbage collection purpose) node.set_next(None) node.set_prev(None) # return the element of the removed node return element def __str__(self): '''(DoubleLinkedList) -> str  returns the items in the DLL in a string form  '''  # define a node, which points to the first node after the head cur = self._head.get_next() # define an empty string to be used as a container for the items in the SLL result = "" # loop over the DLL until you get to the end of the DLL while (cur is not self._tail): # get the element of the current node and attach it to the final result result = result + str(cur.get_element()) + ", " # proceed to next node cur = cur.get_next() # enclose the result in a parantheses result = "(" + result[:-2] + ")" # return the result return result