I'm developing a mobile application backend with Django 1.9.1 I implemented the follower model and now I want to list all of the followers of a user but I'm currently stuck to do that. I also use Django Rest Framework.

This is my UserProfile model

class UserProfile(models.Model):# Linking UserProfile to User model.user = models.OneToOneField(User)city = models.CharField(null=True, max_length=30, blank=True)gender = models.CharField(null=True, max_length=10, blank=True) # m for male, f for female# TODO: Fix the picture later.#  picture = models.ImageField(upload_to='profile_images', blank=True)age = models.IntegerField(null=True, blank=True)caption = models.CharField(null=True, max_length=40, blank=True)following_count = models.IntegerField(default=0)follower_count = models.IntegerField(default=0)post_count = models.IntegerField(default=0)like_count = models.IntegerField(default=0)date = models.DateTimeField(default=datetime.now(), blank=True)is_protected = models.BooleanField(default=False)is_facebook_created_user = models.BooleanField(default=False)facebook_id = models.CharField(default='', blank=True, max_length=350)picture_url = models.URLField(blank=True, max_length=100, null=True)followings = models.ManyToManyField('self', related_name='following', symmetrical=False)followers = models.ManyToManyField('self', related_name='follower', symmetrical=False)blocking = models.ManyToManyField('self', related_name='block', symmetrical=False)blocked_by = models.ManyToManyField('self', related_name='blocked', symmetrical=False)def block_user(self,username):other = UserProfile.objects.get(user__username=username)if not self.is_blocking(username):self.blocking.add(other)other.blocked_by.add(self)return Trueelse:return Falsedef unblock_user(self, username):other = UserProfile.objects.get(user__username=username)if self.is_blocking(username):self.blocking.remove(other)other.blocked_by.remove(self)return Trueelse:return Falsedef follow_user(self, username):other = UserProfile.objects.get(user__username=username)if not self.is_following(username):self.followings.add(other)self.following_count = self.followings.all().count()self.save()other.followers.add(self)other.follower_count = other.followers.all().count()other.save()return Trueelse:return Falsedef unfollow_user(self, username):other = UserProfile.objects.get(user__username=username)if self.is_following(username):self.followings.remove(other)self.following_count = self.followings.all().count()self.save()other.followers.remove(self)other.follower_count = other.followers.all().count()other.save()return Trueelse:return Falsedef is_blocking(self,username):return self.blockings.all().filter(user__username=username).exists()def is_blocked_by(self,username):return self.blocked_by.all().filter(user__username=username).exists()def is_following(self, username):  #returns Boolreturn self.followings.all().filter(user__username=username).exists()def is_followed_by(self, username):  #returns Boolreturn self.followers.all().filter(user__username=username).exists()def __unicode__(self):return self.user.usernamedef get_token(self):try:token = Token.objects.get(user_id=self.user_id)except:token = 'error'return tokendef get_username(self):return self.user.username

As you see, I user ManyToManyField for followers. Now I want to list followers of a user but I don't want to list just all of their information since it's unnecessary. I just want to list their usernames because no need for whole information and it's just a waste.

Here is my followers view.

@api_view(['GET'])
def get_followers(request):username = request.query_params.get('username', None)if username is not None:if        UserProfile.objects.all().filter(user__username=username).exists():wanted = UserProfile.objects.get(user__username=username)followers = wanted.followers.all()serializer = FollowerSerializer(followers)return JsonResponse(serializer.data)else:return JsonResponse({"result": "user_does_not_exist"})else:#TODO: return current user's followersreturn JsonResponse({"result": "provide_username"})

Also I added a serializer for only followers of user.

class FollowerSerializer(serializers.ModelSerializer):class Meta:model = UserProfilefield = ('followers',)

The problem is, it just lists the all of the user information and it doesn't give usernames but it only lists their id's which i can't do anything.

I forgot to mention that I did think of using ListAPIView but I can't get the username parameter with that. If there is a way of getting the parameter, I could also use ListAPIView for followers.

How can I fix this problem and list only their usernames? Any help will be appreciated.

I think what you need is the nested serializer:

class FollowerSerializer(serializers.ModelSerializer):username = serializers.CharField(source='user__username')class Meta:model = UserProfilefields = ('username', )class FollowerSerializer(serializers.ModelSerializer):followers = FollowerSerializer(many=True, read_only=True)class Meta:model = UserProfilefields = ('followers', )