Django 用户不是JSON可序列化的ee

我有这个错误

raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type User is not JSON serializable, 

raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type User is not JSON serializable
[23/Jul/2019 19:16:13] "GET /api/users/profile/ttt/ HTTP/1.1" 500 102886

请帮帮我

def get_followers(self, obj):
        return obj.profile.followers.all()

/////序列化程序.py////////

from django.contrib.auth import get_user_model

User = get_user_model()

class ProfileRetrieveSerializer(serializers.ModelSerializer):
    """
    Serializer that represents a profile.
    """
    queryset=User.objects.all()

    followers = serializers.SerializerMethodField()

    class Meta:
        model = User
        fields = [
           'followers',
        ]

def get_followers(self, obj):
        return obj.profile.followers.all()

/////////////models.py/////////////////

from django.contrib.auth.models import User
from django.db import models

class Profile(models.Model):
    """
    Model that represents a profile.
    """
    user = models.OneToOneField(settings.AUTH_USER_MODEL, 
     related_name='profile', on_delete=models.CASCADE)

    followers = models.ManyToManyField(
        User, related_name='following', blank=True
    )

    class Meta:
        ordering = ('-member_since', )

我得到这个错误

raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type User is not JSON serializable, 

raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type User is not JSON serializable
[23/Jul/2019 19:16:13] "GET /api/users/profile/ttt/ HTTP/1.1" 500 102886

---

必须先序列化用户，才能通过UserSerializer显示跟随者

class UserSerializer(serializers.ModelSerializer): 
    """ Serializer that represents a user. """ 

    class Meta:
        model = User
        fields = [
           'username',
           'first_name',
           'last_name',
        ]

class ProfileRetrieveSerializer(serializers.ModelSerializer): 
    """ Serializer that represents a profile. """ 
    followers = serializers.SerializerMethodField()

    class Meta:
        model = User
        fields = [
           'followers',
        ]
    @staticMethod
    def get_followers(obj):
        return UserSerializer(obj.profile.followers.all(), many=True).data

而观点应如下所示：

from django.contrib.auth import get_user_model

class UserProfileListAPI(ListAPIView)
    queryset=get_user_model().objects.all()
    serializers_class = ProfileRetrieveSerializer

    def get(self,request,*args,**kwargs):
        return self.list(request, *args, **kwargs)