python数据结构之十六进制以下进制转成二进制（栈的应用）

from Stack import *

class f():

    def __init__(self,n,base):
        self.stack=Stack()
        self.n=n
        self.base=base
    def turn(self):
        st='0123456789ABCDEF'

        while self.n!=0:
            d=self.n%self.base
            self.stack.push(d)
            self.n=self.n//self.base
        base_string=''
        for i in range(self.stack.size()):
            base_string=st[self.stack.get_stack()[i]]+base_string

        return base_string



if __name__ == '__main__':
    s=f(15,16)
    print(s.turn())