Implementing the pop method for a stack
In this exercise, you will implement the pop() operation for a stack. pop() will be used to remove an element from the top of the stack. Again, we will consider the size attribute to know the number of elements in the stack.
Recall the Node() class:
class Node:
def __init__(self, data):
self.data = data
self.next = None
This exercise is part of the course
Data Structures and Algorithms in Python
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
class Stack:
def __init__(self):
self.top = None
self.size = 0
def pop(self):
# Check if there is a top element
if self.____ is None:
return None
else:
popped_node = self.top
# Decrement the size of the stack
self.size -= ____
# Update the new value for the top node
self.top = self.____
popped_node.next = None
return popped_node.data