I would like to update certain properties of a user (say first\_name and last\_name)
my json object through a PUT request would look like this

```
   {
"user" :    {   
             "first_name": "Jack",   
             "last_name": "shnider",
             "password":"admin123" 
             "email" : "foo@google.com"
             },

"employee_zip" : 12345
}

```

This is what my view looks like (I would like to update the existing fields to these new fields).

These are the serializer

```
  class Serializer_UpdateUser(ModelSerializer):
    class Meta:
        model = User
        fields = ('first_name','last_name','password')

class Serializer_UpdateEmployer(ModelSerializer):
    user = Serializer_UpdateUser()
    class Meta:
        model = modelEmployer
        fields = [
            'user',
            'employer_zip',
        ]

```

This is the view :

```
class UpdateProfile_RetrieveUpdateAPIView(RetrieveUpdateAPIView):
    queryset = modelEmployer.objects.all()
    serializer_class = Serializer_UpdateEmployer
    lookup_field = 'user__email'
    permission_classes = [permissions.AllowAny]

    def update(self, request, *args, **kwargs):
        instance = self.get_object() #------>I have the object that I would like to update
        serializer = self.get_serializer(instance, data=request.data, partial=partial)
        serializer.is_valid(raise_exception=True) #--->Success

```

Now I would like to get a validated fields (The json only contains the fields that have been updated). I know if I do something like this

```
serializer.save

```

I would get back a modelEmployer but instead I get back this error 

```
AssertionError at /api/employer/update_profile/employerA@gmail.com/ The `.update()` method does not support writable nested fields by default. Write an explicit `.update()` method for serializer `Employer.api.serializers.Serializer_ListEmployer`, or set `read_only=True` on nested serializer fields. Request Method: 

```

I have two questions

1-Why is save failing ?

2-How can I get the validated data from the above serializer ?