python实现支付宝当面付（扫码支付）功能

# ========支付相关配置信息===========
 ALIPAY_INPUT_CHARSET = 'utf-8'
 # 商户ID，以2088开头的16位纯数字
 ALIPAY_PARTNER = '2088************'
 # 服务商支付宝账号
 ALIPAY_SELLER_EMAIL = ''
 # 支付结果回调地址
 ALIPAY_NOTIFY_URL = "商家后台回调接口地址"
 # 访问模式,根据自己的服务器是否支持ssl访问，若支持请选择https；若不支持请选择http
 ALIPAY_TRANSPORT = 'https'
 #签名加密方式
 SIGN_TYPE = "SHA-1"
 #应用id
 APP_ID = '************'
 #下单api
 precreate_GATEWAY=https://openapi.alipay.com/gateway.do?

#1：生成下单请求参数字符串
 def make_payment_request(self,params_dict):
  """
  构造支付请求参数
  :param params_dict:
  :return:
  """
  query_str = self.params_to_query(params_dict,) # 拼接参数字符串
  sign = self.make_sign(query_str) # 生成签名
  sign = urllib.quote(sign, safe='') #解决中文参数编码问题
  res = "%s&sign=%s" % (query_str, sign)
  return res
 def params_to_query(self,params):
  """
  生成需要签名的字符串
  :param params:
  :return:
  """
  """
  :param params:
  :return:
  """
  query = ""
  dict_items = {}
  for key, value in params.items():
   if isinstance(value, dict) == True:
    dict_items[key] = value
    params[key] = "%s"
  all_str = ''
  for key in sorted(params.keys()): #把参数按key值排序：这是支付宝下单请求的参数格式规定
   all_str = all_str + '%s=%s&' % (key, params[key])
  all_str = all_str.rstrip('&')
  biz_content_dict = dict_items['biz_content']
  content_str = ''
  for key in sorted(biz_content_dict.keys()):
   if isinstance(biz_content_dict[key], basestring) == True:
    content_str = content_str + '"%s":"%s",' % (key, biz_content_dict[key])
   else:
    content_str = content_str + '"%s":%s,' % (key, biz_content_dict[key])
  content_str = content_str.rstrip(',')
  content_str = '{' + content_str + '}'
  query = all_str % content_str
  return query
 def make_sign(self,para_str):
  """
  生成签名
  :param message:
  :return:
  """
  private_key = OpenSSL.crypto.load_privatekey(OpenSSL.crypto.FILETYPE_PEM, open(
   './路径/private_key.txt').read()) #把私钥存到一个文件里，加载出来【尝试过用rsa模块的方法加载私钥字符串，会报格式错误。查看源码得知，需要从文件流加载】
  import sys
  reload(sys)
  sys.setdefaultencoding('utf-8') #这三句：解决签名方法编码报错
  sign = base64.encodestring(OpenSSL.crypto.sign(private_key, para_str, 'sha256'))
  return sign

 #获取二维码url
 def getAlipayUrl(self,orderid,goodsName,goodsPrice,**kwargs):
  # 构建公共参数
  params = {}
  params['method'] = 'alipay.trade.precreate'
  params['version'] = '1.0'
  params['app_id'] = self.APP_ID
  params['timestamp'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
  params['charset'] = self.ALIPAY_INPUT_CHARSET
  params['notify_url'] = self.ALIPAY_NOTIFY_URL
  params['sign_type'] = 'RSA2'

  # 构建订单参数
  biz_content = {}
  biz_content['out_trade_no'] = orderid # 订单号
  biz_content['subject'] = goodsName #商品名
  biz_content['total_amount'] = goodsPrice # 价格
  params['biz_content'] = biz_content

  #由参数，生成签名，并且拼接得到下单参数字符串
  encode_params = self.make_payment_request(params)
  #下单
  url = self.precreate_GATEWAY + encode_params
  response = requests.get(url)
  #提取下单响应
  body = response.text
  #解析下单响应json字符串
  body_dict = json.loads(body)
  return_msg = body_dict['alipay_trade_precreate_response']['msg']
  if return_msg == "Success":
    code_url = body_dict['alipay_trade_precreate_response']['qr_code']
    return code_url
  else:
   print "fail msg=============" + return_msg

def aliQRCodeNotify(self, request, *args,**kwargs):
  out_trade_no = kwargs.get("out_trade_no")
  trade_status = kwargs.get("trade_status")
  
  #根据trade_status，判断交易结果：交易成功 or 交易关闭
  #根据out_trade_no 更新订单记录信息