Traceback (most recent call last):


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner

response = get_response(request)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/django/core/handlers/base.py", line 145, in _get_response

response = self.process_exception_by_middleware(e, request)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/django/core/handlers/base.py", line 143, in _get_response

response = response.render()


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/django/template/response.py", line 106, in render

self.content = self.rendered_content


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/response.py", line 70, in rendered_content

ret = renderer.render(self.data, accepted_media_type, context)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/renderers.py", line 724, in render

context = self.get_context(data, accepted_media_type, renderer_context)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/renderers.py", line 656, in get_context

raw_data_put_form = self.get_raw_data_form(data, view, 'PUT', request)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/renderers.py", line 563, in get_raw_data_form

data = serializer.data.copy()


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/serializers.py", line 563, in data

return ReturnDict(ret, serializer=self)


 "/Users/wuqilun/opt/anaconda3/envs/agatha/lib/python3.6/site-packages/rest_framework/utils/serializer_helpers.py", line 18, in __init__

super().__init__(*args, **kwargs)
TypeError: 'NoneType' object is not iterable

Traceback (most recent call last):


 "C:\Users\S10500\AppData\Local\Continuum\anaconda3\lib\site-packages\spyder\widgets\ipythonconsole\client.py", line 575, in show_time

elapsed_time = time.monotonic() - self.t0
TypeError: unsupported operand type(s) for -: 'float' and 'NoneType'
