Insertion at end of circular doubly linked list in python

Python program for Insertion at end of circular doubly linked list. Here problem description and explanation.

#  Python 3 Program 
#  Insert node at end of circular doubly linked list

#  Define class of linked list Node
class LinkNode :
	def __init__(self, data) :
		#  Set node value
		self.data = data
		self.next = None
		self.prev = None
	

class CircularDLL :
	def __init__(self) :
		self.head = None
		self.tail = None
	
	#  Insert node at end of circular doubly linked list
	def insert(self, value) :
		#  Create a node
		node = LinkNode(value)
		if (self.head == None) :
			#  First node of linked list
			self.head = node
			self.tail = node
			node.next = node
			node.prev = node
		else :
			node.next = self.head
			node.prev = self.tail
			self.head.prev = node
			self.tail.next = node
			#  Set new last node
			self.tail = node
		
	
	def headToTail(self) :
		if (self.head == None) :
			print("Empty linked list")
		else :
			temp = self.head
			print("\nNode Form Front to Rear :")
			while (temp != None) :
				print("  ", temp.data, end = "")
				temp = temp.next
				if (temp == self.head) :
					return
				
			
		
	
	def tailToHead(self) :
		if (self.tail == None) :
			print("Empty linked list", end = "")
		else :
			temp = self.tail
			print("\nNode Form Rear to Front :")
			while (temp != None) :
				print("  ", temp.data, end = "")
				temp = temp.prev
				if (temp == self.tail) :
					return
				
			
		
	

def main() :
	cdll = CircularDLL()
	#  Add following linked list nodes
	cdll.insert(1)
	cdll.insert(2)
	cdll.insert(3)
	cdll.insert(4)
	cdll.insert(5)
	cdll.insert(6)
	#  Display node
	cdll.headToTail()
	cdll.tailToHead()

if __name__ == "__main__": main()

Output

Node Form Front to Rear :
   1   2   3   4   5   6
Node Form Rear to Front :
   6   5   4   3   2   1