Find length of loop in linked list in python

Python program for Find length of loop in linked list. Here problem description and explanation.

#  Python 3 Program for 
#  Find length of loop in linked list 
class LinkNode :
	def __init__(self, value) :
		self.data = value
		self.next = None
	

class SingleLL :
	def __init__(self) :
		self.head = None
	
	#  Insert node at last of linke list
	def insert(self, value) :
		#  Create a node
		node = LinkNode(value)
		if (self.head == None) :
			#  First node
			self.head = node
		else :
			temp = self.head
			#  Find lase node
			while (temp.next != None) :
				temp = temp.next
			
			#  Add node
			temp.next = node
		
	
	#  Find the length of loop
	def lengthLoop(self) :
		if (self.head == None) :
			print("Empty Linked List ")
		else :
			#  Case : Check whether if loop
            #         exists in given linked list
			#  Auxiliary variables
			first = self.head
			second = self.head
			counter = 0
			#  Detecting the loop in linked list
			while (second != None and 
                   second.next != None and 
                   second.next.next != None) :
				#  Visit to next node
				first = first.next
				#  Visit to second next node
				second = second.next.next
				if (first == second) :
					#  Loop is found
					counter = 1
					break
				
			
			if (counter == 1) :
				#  Count the length of loop
				while (first.next != second) :
					#  Visit to next node
					first = first.next
					counter += 1
				
			
			print("Length of Loop : ", counter)
		
	

def main() :
	task = SingleLL()
	task.insert(1)
	task.insert(2)
	task.insert(3)
	task.insert(4)
	task.insert(5)
	task.insert(6)
	task.insert(7)
	task.insert(8)
	#  Create Loop
	task.head.next.next.next.next.next.next.next.next = task.head.next.next
	task.lengthLoop()

if __name__ == "__main__": main()

Output

Length of Loop :  6