Stacks and Queues

class stack:

	def __init__(self, data=None):
		self.data = []
		if isinstance(data, list):
			self.data.extend(data)
		elif not data is None:
			self.data.append(data)

	def push(self, data):
		self.data.append(data)

	def pop(self):
		return(self.data.pop())

	def size(self):
		return len(self.data)

	def peek(self);
		return self.data[-1]

	def TIM(self):
		self.push(self.pop()**2)

	def SUM(self):
		self.push(self.pop()*2)


class Queue:

	def __init__(self, vals=None):
		self.data = []
		if isinstance(vals, list):
			self.data.extend(vals)
		elif not val is None:
			self.data.append(vals)

	def enqueue(self, val):
		if isinstance(val, list):
			for v in val:
				self.data.insert(0, v)
		else
			self.data.insert(0, val)

	def dequeue(self):
		if self.size() == 0:
			raise Exception("Queue empty")
		return self.data.pop()

	def Print(self):
	  	for d in self.data:
	  		print(d)

	def size(self):
	   	return len(self.data)