Insert node at beginning of linked list in Python

Write a program which is create and add new node at the beginning of linked list in Python.

Here given of code implementation process.

#  Python 3 program for
#  Insert node at beginning of 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
    
    #  Adding new node at beginning of linked list
    def addNode(self, data) :
        #  Create new node
        node = LinkNode(data)
        #  Connect current node to previous head
        node.next = self.head
        self.head = 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 main() :
    sll = SingleLL()
    #  Linked list
    #  1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → NULL
    sll.addNode(8)
    sll.addNode(7)
    sll.addNode(6)
    sll.addNode(5)
    sll.addNode(4)
    sll.addNode(3)
    sll.addNode(2)
    sll.addNode(1)
    sll.display()

if __name__ == "__main__": main()

 1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → NULL

Time complexity of above program is O(1).