Traceback (most recent call last):
  File "D:\Program Files\Python36\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "D:\Program Files\Python36\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "D:\Program Files\Python36\lib\site-packages\django\views\decorators\csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "D:\Program Files\Python36\lib\site-packages\django\views\generic\base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\views.py", line 509, in dispatch
    response = self.handle_exception(exc)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\views.py", line 469, in handle_exception
    self.raise_uncaught_exception(exc)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\views.py", line 480, in raise_uncaught_exception
    raise exc
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\views.py", line 506, in dispatch
    response = handler(request, *args, **kwargs)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework_simplejwt\views.py", line 27, in post
    serializer.is_valid(raise_exception=True)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\serializers.py", line 220, in is_valid
    self._validated_data = self.run_validation(self.initial_data)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework\serializers.py", line 422, in run_validation
    value = self.validate(value)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework_simplejwt\serializers.py", line 75, in validate
    data['refresh'] = str(refresh)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework_simplejwt\tokens.py", line 82, in __str__
    return token_backend.encode(self.payload)
  File "D:\Program Files\Python36\lib\site-packages\rest_framework_simplejwt\backends.py", line 43, in encode
    return token.decode('utf-8')
AttributeError: 'str' object has no attribute 'decode'

解决办法

方法1

升级 djangorestframework-simplejwt 版本至 4.6.0+

方法2

打开
D:\Program Files\Python36\lib\site-packages\rest_framework_simplejwt\backends.py

文件，编辑第43行。将

return token.decode('utf-8')

return token