用python的json()时报错：simplejson.errors.JSONDecodeError: Expecting value: line 2 column 1 (char 2)

 response=response.json()

File "D:\python\lib\site-packages\requests\models.py", line 910, in json
return complexjson.loads(self.text, **kwargs)
File "D:\python\lib\site-packages\simplejson_init_.py", line 525, in loads
return _default_decoder.decode(s)
File "D:\python\lib\site-packages\simplejson\decoder.py", line 370, in decode
obj, end = self.raw_decode(s)
File "D:\python\lib\site-packages\simplejson\decoder.py", line 400, in raw_decode
return self.scan_once(s, idx=_w(s, idx).end())
simplejson.errors.JSONDecodeError: Expecting value: line 2 column 1 (char 2)