code: def __stringify_request(request_data):
      
      for key, value in request_data.items():
  
          if isinstance(value, list):
              value = json.dumps(value, indent=2, ensure_ascii=False)
  
          elif isinstance(value, bytes):
              try:
                  encoding = "utf-8"
                  value = escape(value.decode(encoding))
              except UnicodeDecodeError:
                  pass
  
          elif not isinstance(value, (basestring, numeric_types, Iterable)):
              # class instance, e.g. MultipartEncoder()
              value = repr(value)
  
          elif isinstance(value, requests.cookies.RequestsCookieJar):
              value = value.get_dict()
  
          request_data[key] = value
docs: stringfy HTTP request data
  
      Args:
          request_data (dict): HTTP request data in dict.
  
              {
                  "url": "http://127.0.0.1:5000/api/get-token",
                  "method": "POST",
                  "headers": {
                      "User-Agent": "python-requests/2.20.0",
                      "Accept-Encoding": "gzip, deflate",
                      "Accept": "*/*",
                      "Connection": "keep-alive",
                      "user_agent": "iOS/10.3",
                      "device_sn": "TESTCASE_CREATE_XXX",
                      "os_platform": "ios",
                      "app_version": "2.8.6",
                      "Content-Type": "application/json",
                      "Content-Length": "52"
                  },
                  "json": {
                      "sign": "cb9d60acd09080ea66c8e63a1c78c6459ea00168"
                  },
                  "verify": false
              }