Python对接支付宝支付自实现功能

# -*- coding: utf-8 -*-import base64import jsonimport urllib.parsefrom datetime import datetimeimport requestsfrom cryptography.hazmat.backends import default_backendfrom cryptography.hazmat.primitives import hashesfrom cryptography.hazmat.primitives import serializationfrom cryptography.hazmat.primitives.asymmetric import paddingclass AliPayException(Exception):  def __init__(self, data):    super(AliPayException, self).__init__()    self.data = data  def __str__(self):    return "alipay - {}".format(self.data)  def __unicode__(self):    return u"alipay - {}".format(self.data)class AliPayVerifyException(AliPayException):  def __init__(self, msg, data):    super(AliPayVerifyException, self).__init__('alipay verify except - {}:{}'.format(msg, data))class AliPay:  def __init__(self, **kwargs):    """    :param kwargs: