return self.items == [] def sPush(self, item): return self.items.append(item) def sPop(self): return self.items.pop() def sPeek(self): return self.items[len(self.items) - 1] def sSize(self): return len(self.items) s1 = Stack() p1 = s1.sIsEmpty() print p1 s1.sPush(3) s1.sPush(4) s1.sPush(-1) s1.sPush(0) s1.sPush(4) s1.sPush(1) s1.sPush(5) print s1.items s1.sPop() print s1.items print(s1.sPeek()) print(s1.sSize())