Differences between revisions 1 and 34 (spanning 33 versions)

Django REST framework

https://www.django-rest-framework.org/

Django REST framework is a powerful and flexible toolkit for building Web APIs.

Quickstart

Check django-rest-test
django shell python3 manage.py shell
Based on https://www.django-rest-framework.org/tutorial/quickstart/#quickstart
https://www.django-rest-framework.org/api-guide/viewsets/
https://www.django-rest-framework.org/api-guide/views/

   1 cd ~/tmp
   2 mkdir django-rest-test
   3 cd django-rest-test
   4 sudo apt install python3-venv
   5 python3 -m venv virtenv
   6 . virtenv/bin/activate
   7 pip install djangorestframework
   8 find . virtenv/
   9 django-admin startproject tutorial . 
  10 cd tutorial
  11 django-admin startapp quickstart
  12 cd ..
  13 python manage.py migrate # sync DB 
  14 python manage.py createsuperuser --email admin@example.com --username admin # create super user, pwd: 12345678 
  15 nano tutorial/quickstart/serializers.py
  16 nano tutorial/quickstart/views.py
  17 nano tutorial/urls.py
  18 nano tutorial/settings.py
  19 nano tutorials/quickstart/apps.py
  20 nano tutorials/quickstart/models.py
  21 
  22 python manage.py runserver
  23 # Starting development server at http://127.0.0.1:8000/
  24 curl -H 'Accept: application/json; indent=4' -u admin:12345678 http://127.0.0.1:8000/users/
  25 
  26 sqlite3 db.sqlite3
  27 .tables 
  28 select * from auth_user;
  29 .exit 
  30 
  31 python3 manage.py collectstatic
  32 mkdir -p static/others
  33 echo "aaaa" > static/others/test.txt
  34 
  35 curl -H 'Accept: application/json' -u admin:1234567 http://127.0.0.1:8000/helloworld/
  36 curl -H 'Accept: application/json' -u admin:12345678 http://127.0.0.1:8000/helloworldanon/
  37 curl http://127.0.0.1:8000/helloworldviewset/
  38 curl http://127.0.0.1:8000/static/others/test.txt
  39 curl -X POST -H "Content-Type:application/json" -u admin:12345678 -d "{\"task\":\"t2\"}"  http://127.0.0.1:8000/tasks/

tutorials/quickstart/apps.py

   1 from django.apps import AppConfig
   2 
   3 class QuickstartConfig(AppConfig):
   4     default_auto_field = 'django.db.models.BigAutoField'
   5     name = 'tutorial.quickstart'

tutorials/quickstart/models.py

   1 from django.db import models
   2 
   3 class Task(models.Model):
   4     created = models.DateTimeField(auto_now_add=True)
   5     task = models.CharField(max_length=128, blank=True, default='')
   6 """
   7 python manage.py makemigrations quickstart
   8 python manage.py migrate
   9 sqlite3 db.sqlite3
  10 .tables 
  11 # quickstart_task
  12 .dump quickstart_task 
  13 PRAGMA foreign_keys=OFF;
  14 BEGIN TRANSACTION;
  15 CREATE TABLE IF NOT EXISTS "quickstart_task" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "created" datetime NOT NULL, "task" varchar(128) NOT NULL);
  16 COMMIT;
  17 .exit 
  18 """

tutorial/quickstart/serializers.py

   1 from django.contrib.auth.models import User, Group
   2 from rest_framework import serializers
   3 from tutorial.quickstart.models import Task
   4 
   5 class UserSerializer(serializers.HyperlinkedModelSerializer):
   6     class Meta:
   7         model = User
   8         fields = ['url', 'username', 'email', 'groups']
   9 
  10 
  11 class GroupSerializer(serializers.HyperlinkedModelSerializer):
  12     class Meta:
  13         model = Group
  14         fields = ['url', 'name']
  15 
  16 class TaskSerializer(serializers.ModelSerializer):
  17     class Meta:
  18         model = Task
  19         fields = ['id','task','created']

tutorial/quickstart/views.py

   1 import json
   2 from django.contrib.auth.models import User, Group
   3 from rest_framework import viewsets,permissions
   4 from tutorial.quickstart.serializers import UserSerializer, GroupSerializer
   5 from django.views.decorators.csrf import csrf_exempt
   6 from rest_framework.authentication import SessionAuthentication, BasicAuthentication
   7 from rest_framework.permissions import IsAuthenticated
   8 from rest_framework.response import Response
   9 from rest_framework.decorators import api_view, authentication_classes, permission_classes
  10 from rest_framework.views import APIView
  11 from tutorial.quickstart.models import Task
  12 from tutorial.quickstart.serializers import TaskSerializer
  13 from django.http import HttpResponse, JsonResponse
  14 from rest_framework.parsers import JSONParser
  15 
  16 class UserViewSet(viewsets.ModelViewSet):
  17     """
  18     API endpoint that allows users to be viewed or edited.
  19     """
  20     queryset = User.objects.all().order_by('-date_joined')
  21     serializer_class = UserSerializer
  22     permission_classes = [permissions.IsAuthenticated]
  23 
  24 
  25 class GroupViewSet(viewsets.ModelViewSet):
  26     """
  27     API endpoint that allows groups to be viewed or edited.
  28     """
  29     queryset = Group.objects.all()
  30     serializer_class = GroupSerializer
  31     permission_classes = [permissions.IsAuthenticated]
  32 
  33 
  34 @csrf_exempt
  35 @api_view(['GET'])
  36 @authentication_classes([SessionAuthentication, BasicAuthentication])
  37 @permission_classes([IsAuthenticated])
  38 def hello_world(request):
  39     """
  40     Function view
  41     """
  42     return Response({"message": "Hello world", "user": str(request.user)})
  43 
  44 
  45 class HelloWorldAnonView(APIView):
  46     def get(self, request, format=None):
  47         return Response({"message": "Hello world anonymous", "user": str(request.user)})
  48 
  49 
  50 class HelloWorldViewSet(viewsets.ViewSet):
  51     # authentication required
  52     permission_classes = [permissions.IsAuthenticated]
  53 
  54     def list(self, request):
  55         return Response({"message": "Hello world view set up and running " + str(request.user)})
  56 
  57 
  58 class TaskViewSet(viewsets.ModelViewSet):
  59     # ModelViewSet
  60     queryset = Task.objects.all().order_by("created")
  61     serializer_class = TaskSerializer
  62     permission_classes = [permissions.IsAuthenticated]
  63 
  64     # # authentication required
  65     # permission_classes = [permissions.IsAuthenticated]
  66 
  67     # def list(self, request):
  68     #     serializer = TaskSerializer(Task.objects.all(), many=True)
  69     #     return Response(serializer.data)
  70 
  71     # def create(self, request):
  72     #     payload = JSONParser().parse(request)
  73     #     serializer = TaskSerializer(data=payload)
  74     #     if serializer.is_valid():
  75     #         serializer.save()
  76     #         return Response(serializer.data, status=201)

tutorial/urls.py

   1 from django.urls import include, path
   2 from rest_framework import routers
   3 from tutorial.quickstart import views
   4 
   5 router = routers.DefaultRouter()
   6 router.register(r'users', views.UserViewSet)
   7 router.register(r'groups', views.GroupViewSet)
   8 router.register(r'helloworldviewset', views.HelloWorldViewSet,basename="helloworldviewset")
   9 router.register(r'tasks', views.TaskViewSet,basename="tasks")
  10 
  11 # Wire up our API using automatic URL routing.
  12 # Additionally, we include login URLs for the browsable API.
  13 urlpatterns = [
  14     path('', include(router.urls)),
  15     path('api-auth/', include('rest_framework.urls', namespace='rest_framework')),
  16     path('helloworld/',views.hello_world),
  17     path('helloworldanon/',views.HelloWorldAnonView.as_view()),
  18 ]

tutorial/settings.py

   1 """
   2 Django settings for tutorial project.
   3 
   4 Generated by 'django-admin startproject' using Django 3.2.5.
   5 
   6 For more information on this file, see
   7 https://docs.djangoproject.com/en/3.2/topics/settings/
   8 
   9 For the full list of settings and their values, see
  10 https://docs.djangoproject.com/en/3.2/ref/settings/
  11 """
  12 
  13 from pathlib import Path
  14 import os
  15 import sys
  16 # Build paths inside the project like this: BASE_DIR / 'subdir'.
  17 BASE_DIR = Path(__file__).resolve().parent.parent
  18 
  19 # Quick-start development settings - unsuitable for production
  20 # See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/
  21 
  22 # SECURITY WARNING: keep the secret key used in production secret!
  23 SECRET_KEY = 'django-insecure-j8vs^2rq97)%g%v4fk-nl(3pho4ve)=6%&$**0++$p%v514r8r'
  24 
  25 # SECURITY WARNING: don't run with debug turned on in production!
  26 DEBUG = True
  27 
  28 ALLOWED_HOSTS = []
  29 
  30 
  31 # Application definition
  32 
  33 INSTALLED_APPS = [
  34     'django.contrib.admin',
  35     'django.contrib.auth',
  36     'django.contrib.contenttypes',
  37     'django.contrib.sessions',
  38     'django.contrib.messages',
  39     'django.contrib.staticfiles',
  40     'rest_framework',
  41     'tutorial.quickstart.apps.QuickstartConfig',
  42 ]
  43 
  44 MIDDLEWARE = [
  45     'django.middleware.security.SecurityMiddleware',
  46     'django.contrib.sessions.middleware.SessionMiddleware',
  47     'django.middleware.common.CommonMiddleware',
  48     'django.middleware.csrf.CsrfViewMiddleware',
  49     'django.contrib.auth.middleware.AuthenticationMiddleware',
  50     'django.contrib.messages.middleware.MessageMiddleware',
  51     'django.middleware.clickjacking.XFrameOptionsMiddleware',
  52 ]
  53 
  54 ROOT_URLCONF = 'tutorial.urls'
  55 
  56 TEMPLATES = [
  57     {
  58         'BACKEND': 'django.template.backends.django.DjangoTemplates',
  59         'DIRS': [],
  60         'APP_DIRS': True,
  61         'OPTIONS': {
  62             'context_processors': [
  63                 'django.template.context_processors.debug',
  64                 'django.template.context_processors.request',
  65                 'django.contrib.auth.context_processors.auth',
  66                 'django.contrib.messages.context_processors.messages',
  67             ],
  68         },
  69     },
  70 ]
  71 
  72 WSGI_APPLICATION = 'tutorial.wsgi.application'
  73 
  74 
  75 # Database
  76 # https://docs.djangoproject.com/en/3.2/ref/settings/#databases
  77 
  78 DATABASES = {
  79     'default': {
  80         'ENGINE': 'django.db.backends.sqlite3',
  81         'NAME': BASE_DIR / 'db.sqlite3',
  82     }
  83 }
  84 
  85 
  86 # Password validation
  87 # https://docs.djangoproject.com/en/3.2/ref/settings/#auth-password-validators
  88 
  89 AUTH_PASSWORD_VALIDATORS = [
  90     {
  91         'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
  92     },
  93     {
  94         'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
  95     },
  96     {
  97         'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
  98     },
  99     {
 100         'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
 101     },
 102 ]
 103 
 104 
 105 # Internationalization
 106 # https://docs.djangoproject.com/en/3.2/topics/i18n/
 107 
 108 LANGUAGE_CODE = 'en-us'
 109 
 110 TIME_ZONE = 'UTC'
 111 
 112 USE_I18N = True
 113 
 114 USE_L10N = True
 115 
 116 USE_TZ = True
 117 
 118 
 119 # Static files (CSS, JavaScript, Images)
 120 # https://docs.djangoproject.com/en/3.2/howto/static-files/
 121 
 122 STATIC_URL = '/static/'
 123 STATIC_ROOT = os.path.join(BASE_DIR, 'static')
 124 STATICFILES_DIRS = (
 125     ("others", os.path.join(STATIC_ROOT,'others')),
 126 )
 127 
 128 # Default primary key field type
 129 # https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
 130 
 131 DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
 132 
 133 REST_FRAMEWORK = {
 134     'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
 135     'PAGE_SIZE': 10
 136 }

Queryset

https://docs.djangoproject.com/en/3.2/ref/models/querysets/#queryset-api-reference

Foreign keys and related names, _set

Instance members in model instances are created based on identified relations. Usually those members end with _set.

https://docs.djangoproject.com/en/3.2/ref/models/fields/#foreignkey

A many-to-one relationship. Requires two positional arguments: the class to which the model is related and the on_delete option.

https://docs.djangoproject.com/en/3.2/topics/db/models/#be-careful-with-related-name-and-related-query-name

If you don’t specify a related_name attribute for a field in an abstract base class, the default reverse name will be the name of the child class followed by '_set', just as it normally would be if you’d declared the field directly on the child class. For example, in the above code, if the related_name attribute was omitted, the reverse name for the m2m field would be childa_set in the ChildA case and childb_set for the ChildB field.

Related manager

https://docs.djangoproject.com/en/3.2/ref/models/relations/#related-objects-reference

A “related manager” is a manager used in a one-to-many or many-to-many related context.

-  ⇤ ← Revision 1 as of 2021-07-20 10:32:23 → 
  Size: 1015
  Editor: localhost
  Comment:
+   ← Revision 34 as of 2021-08-20 09:53:14 → ⇥
  Size: 12130
  Editor: localhost
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
+## page was renamed from DjangoREST
-Line 2:
+Line 3:
- * https://www.django-rest-framework.org/tutorial/quickstart/#quickstart
+ * https://www.django-rest-framework.org/
-Line 6:
+Line 7:
+ * Check [[https://github.com/vborrego/django-rest-test|django-rest-test]]
 * django shell ```python3 manage.py shell```
-Line 7:
+Line 10:
+ * https://www.django-rest-framework.org/api-guide/viewsets/
 * https://www.django-rest-framework.org/api-guide/views/
-Line 26:
+Line 32:
+nano tutorials/quickstart/apps.py
nano tutorials/quickstart/models.py
-Line 28:
+Line 37:
-curl -H 'Accept: application/json; indent=4' -u admin:12345678 
}}}
+curl -H 'Accept: application/json; indent=4' -u admin:12345678 http://127.0.0.1:8000/users/

sqlite3 db.sqlite3
.tables 
select * from auth_user;
.exit 

python3 manage.py collectstatic
mkdir -p static/others
echo "aaaa" > static/others/test.txt

curl -H 'Accept: application/json' -u admin:1234567 http://127.0.0.1:8000/helloworld/
curl -H 'Accept: application/json' -u admin:12345678 http://127.0.0.1:8000/helloworldanon/
curl http://127.0.0.1:8000/helloworldviewset/
curl http://127.0.0.1:8000/static/others/test.txt
curl -X POST -H "Content-Type:application/json" -u admin:12345678 -d "{\"task\":\"t2\"}"  http://127.0.0.1:8000/tasks/
}}}

=== tutorials/quickstart/apps.py ===
{{{#!highlight python
from django.apps import AppConfig

class QuickstartConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'tutorial.quickstart'

}}}

=== tutorials/quickstart/models.py ===
{{{#!highlight python
from django.db import models

class Task(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    task = models.CharField(max_length=128, blank=True, default='')
"""
python manage.py makemigrations quickstart
python manage.py migrate
sqlite3 db.sqlite3
.tables 
# quickstart_task
.dump quickstart_task 
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE IF NOT EXISTS "quickstart_task" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "created" datetime NOT NULL, "task" varchar(128) NOT NULL);
COMMIT;
.exit 
"""
}}}

=== tutorial/quickstart/serializers.py ===
{{{#!highlight python
from django.contrib.auth.models import User, Group
from rest_framework import serializers
from tutorial.quickstart.models import Task

class UserSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = User
        fields = ['url', 'username', 'email', 'groups']


class GroupSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Group
        fields = ['url', 'name']

class TaskSerializer(serializers.ModelSerializer):
    class Meta:
        model = Task
        fields = ['id','task','created']
}}}

=== tutorial/quickstart/views.py ===
{{{#!highlight python
import json
from django.contrib.auth.models import User, Group
from rest_framework import viewsets,permissions
from tutorial.quickstart.serializers import UserSerializer, GroupSerializer
from django.views.decorators.csrf import csrf_exempt
from rest_framework.authentication import SessionAuthentication, BasicAuthentication
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.decorators import api_view, authentication_classes, permission_classes
from rest_framework.views import APIView
from tutorial.quickstart.models import Task
from tutorial.quickstart.serializers import TaskSerializer
from django.http import HttpResponse, JsonResponse
from rest_framework.parsers import JSONParser

class UserViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows users to be viewed or edited.
    """
    queryset = User.objects.all().order_by('-date_joined')
    serializer_class = UserSerializer
    permission_classes = [permissions.IsAuthenticated]


class GroupViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows groups to be viewed or edited.
    """
    queryset = Group.objects.all()
    serializer_class = GroupSerializer
    permission_classes = [permissions.IsAuthenticated]


@csrf_exempt
@api_view(['GET'])
@authentication_classes([SessionAuthentication, BasicAuthentication])
@permission_classes([IsAuthenticated])
def hello_world(request):
    """
    Function view
    """
    return Response({"message": "Hello world", "user": str(request.user)})


class HelloWorldAnonView(APIView):
    def get(self, request, format=None):
        return Response({"message": "Hello world anonymous", "user": str(request.user)})


class HelloWorldViewSet(viewsets.ViewSet):
    # authentication required
    permission_classes = [permissions.IsAuthenticated]

    def list(self, request):
        return Response({"message": "Hello world view set up and running " + str(request.user)})


class TaskViewSet(viewsets.ModelViewSet):
    # ModelViewSet
    queryset = Task.objects.all().order_by("created")
    serializer_class = TaskSerializer
    permission_classes = [permissions.IsAuthenticated]

    # # authentication required
    # permission_classes = [permissions.IsAuthenticated]

    # def list(self, request):
    #     serializer = TaskSerializer(Task.objects.all(), many=True)
    #     return Response(serializer.data)

    # def create(self, request):
    #     payload = JSONParser().parse(request)
    #     serializer = TaskSerializer(data=payload)
    #     if serializer.is_valid():
    #         serializer.save()
    #         return Response(serializer.data, status=201)        
}}}

=== tutorial/urls.py ===
{{{#!highlight python
from django.urls import include, path
from rest_framework import routers
from tutorial.quickstart import views

router = routers.DefaultRouter()
router.register(r'users', views.UserViewSet)
router.register(r'groups', views.GroupViewSet)
router.register(r'helloworldviewset', views.HelloWorldViewSet,basename="helloworldviewset")
router.register(r'tasks', views.TaskViewSet,basename="tasks")

# Wire up our API using automatic URL routing.
# Additionally, we include login URLs for the browsable API.
urlpatterns = [
    path('', include(router.urls)),
    path('api-auth/', include('rest_framework.urls', namespace='rest_framework')),
    path('helloworld/',views.hello_world),
    path('helloworldanon/',views.HelloWorldAnonView.as_view()),
]
}}}

=== tutorial/settings.py ===
{{{#!highlight python
"""
Django settings for tutorial project.

Generated by 'django-admin startproject' using Django 3.2.5.

For more information on this file, see
https://docs.djangoproject.com/en/3.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.2/ref/settings/
"""

from pathlib import Path
import os
import sys
# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent

# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-j8vs^2rq97)%g%v4fk-nl(3pho4ve)=6%&$**0++$p%v514r8r'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'tutorial.quickstart.apps.QuickstartConfig',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'tutorial.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'tutorial.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.2/howto/static-files/

STATIC_URL = '/static/'
STATIC_ROOT = os.path.join(BASE_DIR, 'static')
STATICFILES_DIRS = (
    ("others", os.path.join(STATIC_ROOT,'others')),
)

# Default primary key field type
# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
    'PAGE_SIZE': 10
}
}}}

== Queryset ==
 * https://docs.djangoproject.com/en/3.2/ref/models/querysets/#queryset-api-reference


== Foreign keys and related names, _set ==
Instance members in model instances are created based on identified relations. Usually those members end with _set. 

 * https://docs.djangoproject.com/en/3.2/ref/models/fields/#foreignkey
{{{
A many-to-one relationship. Requires two positional arguments: the class to which the model is related and the on_delete option.
}}}
 * https://docs.djangoproject.com/en/3.2/topics/db/models/#be-careful-with-related-name-and-related-query-name
{{{
If you don’t specify a related_name attribute for a field in an abstract base class, the default reverse name will be the name of the child class followed by '_set', just as it normally would be if you’d declared the field directly on the child class. For example, in the above code, if the related_name attribute was omitted, the reverse name for the m2m field would be childa_set in the ChildA case and childb_set for the ChildB field.
}}}

== Related manager ==
 * https://docs.djangoproject.com/en/3.2/ref/models/relations/#related-objects-reference
A “related manager” is a manager used in a one-to-many or many-to-many related context.