Delete a node from the end of doubly linked list in python

Python program for Delete a node from the end of doubly linked list. Here problem description and explanation.

#  Python 3 program for
#  Delete a node from the end of doubly linked list
class LinkNode :
	def __init__(self, data) :
		self.data = data
		self.next = None
		self.prev = None
	

class DoublyLinkedList :
	def __init__(self) :
		self.head = None
		self.tail = None
	
	#  Insert new node at end position
	def insert(self, value) :
		#  Create a node
		node = LinkNode(value)
		if (self.head == None) :
			#  Add first node
			self.head = node
			self.tail = node
			return
		
		#  Add node at last position
		self.tail.next = node
		node.prev = self.tail
		self.tail = node
	
	#  Display node element of doubly linked list
	def display(self) :
		if (self.head == None) :
			print("Empty Linked List")
		else :
			print("\nLinked List Head to Tail : ")
			#  Get first node of linked list
			temp = self.head
			#  iterate linked list 
			while (temp != None) :
				#  Display node value
				print("", temp.data, end = " ")
				#  Visit to next node
				temp = temp.next
			
		
	
	#  Remove the given node from end of linked list
	def deletionFromEnd(self, key) :
		if (self.head == None) :
			#  Empty linked list
			return
		
		auxiliary = None
		temp = self.tail
		#  Find the deleted node
		while (temp != None and auxiliary == None) :
			if (temp.data == key) :
				#  We found deleted node
				auxiliary = temp
			
			#  Visit to previous node
			temp = temp.prev
		
		if (auxiliary != None) :
			#  When we get deleted node
			if (auxiliary.prev != None) :
				#  When previous node present
				auxiliary.prev.next = auxiliary.next
			
			if (auxiliary.next != None) :
				#  When next node present
				auxiliary.next.prev = auxiliary.prev
			
			if (self.head == auxiliary) :
				#  When delete head node
				self.head = self.head.next
			
			if (auxiliary == self.tail) :
				#  When delete last node
				self.tail = self.tail.prev
			
			auxiliary = None
		else :
			print("\nNode not exist ", key)
		
	

def main() :
	dll = DoublyLinkedList()
	#  Insert following linked list nodes
	dll.insert(1)
	dll.insert(2)
	dll.insert(9)
	dll.insert(4)
	dll.insert(5)
	dll.insert(2)
	dll.insert(7)
	dll.insert(9)
	print("\nBefore Delete", end = "")
	dll.display()
	key = 2
	dll.deletionFromEnd(key)
	print("\nAfter Delete Node ", key, end = "")
	dll.display()

if __name__ == "__main__": main()

Output

Before Delete
Linked List Head to Tail :
 1  2  9  4  5  2  7  9
After Delete Node  2
Linked List Head to Tail :
 1  2  9  4  5  7  9