Make the middle node head in a linked list in python

Python program for Make the middle node head in a linked list. Here problem description and explanation.

#  Python 3 Program for
#  Make the middle node as head of singly linked list

#  Linked list node
class LinkNode :
	def __init__(self, data) :
		self.data = data
		self.next = None
	

class SingleLL :
	def __init__(self) :
		self.head = None
		self.tail = None
	
	#  Add new node at the end of linked list
	def addNode(self, value) :
		#  Create a new node
		node = LinkNode(value)
		if (self.head == None) :
			self.head = node
		else :
			self.tail.next = node
		
		self.tail = node
	
	#  Display linked list element
	def display(self) :
		if (self.head == None) :
			return
		
		temp = self.head
		#  iterating linked list elements
		while (temp != None) :
			print(temp.data , end = " → ")
			#  Visit to next node
			temp = temp.next
		
		print("NULL")
	
	def makeMiddleToHead(self) :
		if (self.head == None) :
			print("Empty Linked List")
		else :
			middle = None
			temp = self.head
			#  Find the middle node
			while (temp != None and temp.next != None and 
                   temp.next.next != None) :
				if (middle == None) :
					middle = temp
				else :
					middle = middle.next
				
				temp = temp.next.next
			
			if (middle == None) :
				#  Less then 3 nodes
				print("Less then three element")
			else :
				#  Swap nodes link
				temp = middle.next
				middle.next = temp.next
				temp.next = self.head
				self.head = temp
			
		
	

def main() :
	sll = SingleLL()
	#  Linked list
	#  1 → 2 → 3 → 4 → 5 → 6 → 7 → null
	sll.addNode(1)
	sll.addNode(2)
	sll.addNode(3)
	sll.addNode(4)
	sll.addNode(5)
	sll.addNode(6)
	sll.addNode(7)
	print("Before Linked List ")
	sll.display()
	sll.makeMiddleToHead()
	print("After Linked List ")
	sll.display()

if __name__ == "__main__": main()

Output

Before Linked List
1 → 2 → 3 → 4 → 5 → 6 → 7 → NULL
After Linked List
4 → 1 → 2 → 3 → 5 → 6 → 7 → NULL