stack.py

class Stack:

    def __init__(self) -> None:
        self.items = []

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

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

    def peek(self):
        return self.items[-1]

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

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


def par_checker(symbol_string: str) -> bool:
    s = Stack()
    balanced = True
    index = 0
    while index < len(symbol_string) and balanced:
        symbol = symbol_string[index]
        if symbol == '(':
            s.push(symbol)
        else:
            if s.is_empty():
                balanced = False
            else:
                s.pop()
        index += 1

    if s.is_empty() and balanced:
        return True
    else:
        return False


def divid_by_2(decimal: int) -> str:
    string = ''
    s = Stack()

    while decimal > 0:
        rem = decimal % 2
        s.push(rem)
        decimal = decimal//2

    while not s.is_empty():
        string += str(s.pop())

    return string


if __name__ == "__main__":
    while True:
        s = input('input:')
        print(divid_by_2(int(s)))