﻿ Python Linked List: Insert an item in front of a given doubly linked list - w3resource

# Python Linked List: Insert an item in front of a given doubly linked list

## Python Linked List: Exercise-12 with Solution

Write a Python program to insert an item in front of a given doubly linked list.

Sample Solution:

Python Code:

``````class Node(object):
def __init__(self, data=None, next=None, prev=None):
self.data = data
self.next = next
self.prev = prev

def __init__(self):
self.tail = None
self.count = 0

def append_item(self, data):
# Append an item
new_item = Node(data, None, None)
else:
new_item.prev = self.tail
self.tail.next = new_item
self.tail = new_item
self.count += 1

def iter(self):
# Iterate the list
while current:
item_val = current.data
current = current.next
yield item_val

def print_foward(self):
for node in self.iter():
print(node)

def insert_start(self, data):
new_node = Node(data, None, None)
self.count += 1

items.append_item('PHP')
items.append_item('Python')
items.append_item('C#')
items.append_item('C++')
items.append_item('Java')
items.append_item('SQL')

print("Original list:")
items.print_foward()
print("\nAppend item in front of the list:")
items.insert_start("Perl")
items.print_foward()
```
```

Sample Output:

```Original list:
PHP
Python
C#
C++
Java
SQL

Append item in front of the list:
Perl
PHP
Python
C#
C++
Java
SQL
```

Flowchart:

Python Code Editor: