Check linked list is circular or not in python

Python program for Check linked list is circular or not . Here problem description and explanation.

#  Python 3 Program for
#  Check linked list is circular or not

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

class LinkedList :
	#  Class constructor
	def __init__(self) :
		self.head = None
	
	#  Check circular linked list or not
	#  Note that this function is not capable to detect loop
	def isCircular(self) :
		if (self.head == None) :
			#  Case when linked list is empty
			return False
		else :
			temp = self.head
			while (temp != None) :
				#  Visit to next node
				temp = temp.next
				if (temp == self.head) :
					#  When detecting circular node
					return True
				
			
			#  When not circular linked list
			return False
		
	

def main() :
	ll = LinkedList()
	#  insert element of linked list
	ll.head = LinkNode(1)
	ll.head.next = LinkNode(2)
	ll.head.next.next = LinkNode(3)
	ll.head.next.next.next = LinkNode(4)
	ll.head.next.next.next.next = LinkNode(5)
	if (ll.isCircular()) :
		print("Yes")
	else :
		print("No")
	
	#  Connect last node to head
	ll.head.next.next.next.next.next = ll.head
	if (ll.isCircular()) :
		print("Yes")
	else :
		print("No")
	

if __name__ == "__main__": main()

Output

No
Yes