stacks_queues.py

class Stack:
  def __init__(self):
    self.data = []
  
  def push(self, i):
    self.data.append(i)
  
  def peek(self):
    return self.data[-1]
  
  def pop(self):
    i = self.peek()
    del self.data[-1]
    return i
  
  def size(self):
    return len(self.data)
  
  def isEmpty(self):
    return self.size() <= 0
  
  def print(self):
    print(self.data)

class Queue:
  def __init__(self):
    self.data = []
  
  def enqueue(self, i):
    self.data.insert(0, i)
  
  def dequeue(self):
    i = self.data[-1]
    del self.data[-1]
    return i
  
  def peek(self):
    return self.data[0]
  
  def size(self):
    return len(self.data)
  
  def isEmpty(self):
    return self.size() <= 0
  
  def print(self):
    print(self.data)

# Testing
stack = Stack()
stack.push(7)
stack.push(8)
stack.pop()
stack.push(stack.pop()*3)
stack.print()

queue = Queue()
queue.enqueue(3)
queue.enqueue(3)
queue.enqueue(queue.dequeue()*3)
queue.enqueue(5)
queue.enqueue(queue.dequeue()*3)
queue.enqueue(503)
queue.print()