class Pile:
	
	def __init__(self):
		self.valeurs = []
		
	def empiler(self, valeur):
		self.valeurs.append(valeur)
		
	def depiler(self):
		if self.valeurs:
			return self.valeurs.pop()
			
	def estVide(self):
		return self.valeurs == []
		
	
	def __str__(self):
		ch = ''
		for x in self.valeurs:
			ch = "|\t" + str(x) + "\t|" + "\n" + ch
		ch = "\nEtat de la pile:\n" + ch
		return ch
			
			
			
p = Pile()
p.empiler(9)
p.empiler(2)
p.empiler(5)
print(p)

p.depiler()
p.empiler(7)
print(p.estVide())
print(p)