python根据密钥得到谷歌两步验证动态验证码

# coding=utf-8

import time
import base64
import sys
import hashlib
import hmac
import struct


def google_code(secret_key):
    key = base64.b32decode(secret_key)
    msg = struct.pack(">Q", int(time.time()) // 30)
    code = hmac.new(key, msg, hashlib.sha1).digest()

    # 版本判断
    if sys.version_info > (2, 7):
        o = code[19] & 15
    else:
        o = ord(code[19]) & 15
    code = str((struct.unpack(">I", code[o:o + 4])[0] & 0x7fffffff) % 1000000)

    # 如果第一位是0，则不会显示，判断若是5位码，就在第一位补上0
    if len(code) == 5:
        code = '0' + code
    print(code)
    return code


google_code('密钥')