Python - Making your class Iterable

If we want objects of this class to be used in iteration contexts, then they should support the iteration protocol. To make this class iterable, we can add a __iter__ method to this class.

class Stack:
    def __init__(self):
        self.items = []

    def is_empty(self):
        return self.items == []

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

    def push(self, item):
        self.items.append(item)

    def pop(self):
        if self.is_empty():
            raise RuntimeError("Stack is empty")
        return self.items.pop()

    def display(self):
        print(self.items)

    def __iter__(self):
        return iter(self.items)


stack = Stack()
stack.push(20)
stack.push(30)
stack.push(10)
stack.push(89)
for item in stack:
    print(item)
print(min(stack), max(stack), sum(stack))

Output-

20

30

10

89

10 89 149