python - Python3, json causes TypeError but simplejson doesn't -

i'm running latest python3 (with anaconda distribution) , have problem standard library installed json causes traceback:

    traceback (most recent call last):       file "c:\users\think\anaconda3\lib\site-packages\werkzeug\serving.py", line 193, in run_wsgi         execute(self.server.app)       file "c:\users\think\anaconda3\lib\site-packages\werkzeug\serving.py", line 181, in execute         application_iter = app(environ, start_response)       file "c:\users\think\my_server.py", line 148, in __call__         return self.wsgi_app(environ, start_response)       file "c:\users\think\my_server.py", line 144, in wsgi_app         response = self.dispatch_request(request)       file "c:\users\think\my_server.py", line 80, in dispatch_request         return getattr(self, 'on_' + endpoint)(request, **values)       file "c:\users\think\my_server.py", line 54, in on_xapi_request         json_data = self.load_json(request.data)       file "c:\users\think\my_server.py", line 60, in load_json         return json.loads(data)       file "c:\users\think\anaconda3\lib\json\__init__.py", line 312, in loads         s.__class__.__name__))  typeerror: json object must str, not 'bytes' 

but, simplejson doesn't cause error.

use str.decode('utf-8') before passing json.loads

i think line:

return json.loads(data) 

is causing problem. decode data before passing function.