《python语言程序设计》第8章第8题将二进制数作为字符串转换十进制

def binary_to_decimal(binary_string):
    a = ""
    number_te = ''
    c = ''
    len_text = len(binary_string)
    for i in range(0, len_text):
        a = binary_string[i]
        if binary_string[i] == '0':
            number_te = 0
        elif binary_string[i] == '1':
            number_te = 1
        number_te+=number_te*(2**i)
    print(number_te)


binary_to_decimal("10001")