现象：数据库中手机号码已注册，只是提交注册后页面不能自动跳转到首页
提示报错如下：

[21/Feb/2020 15:21:19] "OPTIONS /users/ HTTP/1.1" 200 0
Internal Server Error: /users/
Traceback (most recent call last):
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\fields.py", line 454, in get_attribute
    return get_attribute(instance, self.source_attrs)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\fields.py", line 94, in get_attribute
    instance = getattr(instance, attr)
AttributeError: 'User' object has no attribute 'code'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\django\core\handlers\base.py", line 115, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\django\core\handlers\base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\django\views\decorators\csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\viewsets.py", line 114, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\views.py", line 505, in dispatch
    response = self.handle_exception(exc)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\views.py", line 465, in handle_exception
    self.raise_uncaught_exception(exc)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\views.py", line 476, in raise_uncaught_exception
    raise exc
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\views.py", line 502, in dispatch
    response = handler(request, *args, **kwargs)
  File "D:\iProj\py37\bm3720\apps\users\views.py", line 86, in create
    re_dict = serializer.data
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\serializers.py", line 562, in data
    ret = super().data
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\serializers.py", line 260, in data
    self._data = self.to_representation(self.instance)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\serializers.py", line 516, in to_representation
    attribute = field.get_attribute(instance)
  File "C:\Documents and Settings\Administrator\Envs\bm3720\lib\site-packages\rest_framework\fields.py", line 487, in get_attribute
    raise type(exc)(msg)
AttributeError: Got AttributeError when attempting to get a value for field `code` on serializer `UserRegSerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `User` instance.
Original exception text was: 'User' object has no attribute 'code'.
[21/Feb/2020 15:21:20] "POST /users/ HTTP/1.1" 500 21924

搜索网上资料，
https://blog.csdn.net/zsx1314lovezyf/article/details/101037289
serializer他会拿code做序列化然而code被我们给delete掉了—解决方案在code加上write_only=True
但是在user的serializer中已加