Python Program for Deleting a Node in a Linked List

# A complete working Python3 program to
# demonstrate deletion in singly 
# linked list with class 

# Node class 
class Node: 

    # Constructor to initialize the node object 
    def __init__(self, data): 
        self.data = data 
        self.next = None

class LinkedList: 

    # Function to initialize head 
    def __init__(self): 
        self.head = None

    # Function to insert a new node at the beginning 
    def push(self, new_data): 
        new_node = Node(new_data) 
        new_node.next = self.head 
        self.head = new_node 

    # Given a reference to the head of a list and a key, 
    # delete the first occurrence of key in linked list 
    def deleteNode(self, key): 
        
        # Store head node 
        temp = self.head 

        # If head node itself holds the key to be deleted 
        if (temp is not None): 
            if (temp.data == key): 
                self.head = temp.next
                temp = None
                return

        # Search for the key to be deleted, keep track of the 
        # previous node as we need to change 'prev.next' 
        while(temp is not None): 
            if temp.data == key: 
                break
            prev = temp 
            temp = temp.next

        # if key was not present in linked list 
        if(temp == None): 
            return

        # Unlink the node from linked list 
        prev.next = temp.next

        temp = None


    # Utility function to print the linked LinkedList 
    def printList(self): 
        temp = self.head 
        while(temp): 
            print (" %d" %(temp.data)), 
            temp = temp.next


# Driver program 
llist = LinkedList() 
llist.push(7) 
llist.push(1) 
llist.push(3) 
llist.push(2) 

print ("Created Linked List: ")
llist.printList() 
llist.deleteNode(1) 
print ("Linked List after Deletion of 1:")
llist.printList() 

# This code is contributed by Nikhil Kumar Singh (nickzuck_007) & edited by Sayan Biswas (dankguy6146)