I am trying to learn Linked Lists in python. I was given the Linked List class and asked to create an append method.
Here is the code.
class Node:
def __init__(self, item, next):
self.item = item
self.next = next
class LinkedList:
def __init__(self):
self.head = None
def add(self, item):
self.head = Node(item, self.head)
def remove(self):
if self.is_empty():
return None
else:
item = self.head.item
self.head = self.head.next
return item
def is_empty(self):
return self.head == None
def __str__(self):
tmp_str = ""
ptr = self.head
while ptr != None:
tmp_str += ptr.item + " "
ptr = ptr.next
return tmp_str
Here is my append method, but something is wrong with it. I know that if the linked list is empty, I have to create it, the problem starts when there are elements inside.
def append(self, item):
ptr = self.head
if ptr:
while ptr != None:
ptr = ptr.next
ptr = Node(item, ptr)
else:
self.head = Node(item, self.head)
Can anyone tell me what I did wrong? Any help is greatly appreciated.
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