circular_linked_list.py

conclass Node: 
      
    # Constructor to create  a new node 
    def __init__(self, data): 
        self.data = data  
        self.next = None
  
class CircularLinkedList: 
      
    # Constructor to create a empty circular linked list 
    def __init__(self): 
        self.head = None
  
    # Function to insert a node at the beginning of a 
    # circular linked list 
    def push(self, data): 
        ptr1 = Node(data) 
        temp = self.head 
          
        ptr1.next = self.head 
  
        # If linked list is not None then set the next of 
        # last node 
        if self.head is not None: 
            while(temp.next != self.head): 
                temp = temp.next 
            temp.next = ptr1 
  
        else: 
            ptr1.next = ptr1 # For the first node 
  
        self.head = ptr1  
  
    # Function to print nodes in a given circular linked list 
    def printList(self): 
        temp = self.head 
        if self.head is not None: 
            while(True): 
                print ("{}".format(temp.data))
                temp = temp.next
                if (temp == self.head): 
                    break 
  
  
# Driver program to test above function 
  
# Initialize list as empty 
cllist = CircularLinkedList() 
  
# Created linked list will be 11->2->56->12 
cllist.push(12) 
cllist.push(56) 
cllist.push(2) 
cllist.push(11) 
  
print "Contents of circular Linked List"
cllist.printList()