Name : Abdullah Numan Shakil.
Dept. of Computer Science & Engineering.
University of Rajshahi.

Steps of Creating an API With API Documentation

Before all, python must be installed in system

Step-1: Creating virtual environment

Create an empty folder "Practice". Inside the folder create virtual environment
python -m venv env

Step-2: Activation of virtual envvironment

Activate the virtual environment
cd env
cd Scripts
activate

Step-3: Django and rest framework installtion

Go back to the project folder "Practice" and install Django and rest framework
pip install django
pip install djangorestframework

Step-4: Creating Project

Create a new Django project "catproject"
django-admin startproject catproject

Step-5: Run Project

Run the project if it is working properly
python manage.py runserver

Step-5: Creating app

Create a new app "catapp"
python manage.py startapp catapp

Step-6: Including app in project

Go to the settings.py file inside catproject and add 'catapp' and 'rest_framework' in INSTALLED_APPS

Steps-7: Implemienting the app

Go to the "catapp" folder.
Implement The model inside models.py
Create serializers.py and implement serializer including all fields of the model.
In views.py implement CRUD operations for the model
Create urls.py and define the urls
Go to the urls.py in "catproject" and include urls.py of the "catapp"

Steps-8: Documentation

Install the module pip install drf-yasg
Go to settings.py and add this 'drf_yasg', in INSTALLED_APPS
Go to urls.py in "catproject" and add the code snippet

from django.urls import re_path
from rest_framework import permissions
from drf_yasg.views import get_schema_view
from drf_yasg import openapi

schema_view = get_schema_view(
   openapi.Info(
      title="Dog API",
      default_version='v1',
      description="Documentation",
      terms_of_service="https://www.google.com/policies/terms/",
      contact=openapi.Contact(email="contact@dogapp.local"),
      license=openapi.License(name="BSD License"),
   ),
   public=True,
   permission_classes=(permissions.AllowAny,),
)

urlpatterns = [
    path('documentation.json/', schema_view.without_ui(cache_timeout=0), name='schema-json'),
    path('documentation/', schema_view.with_ui('swagger', cache_timeout=0), name='schema-swagger-ui'),
    path('redoc/', schema_view.with_ui('redoc', cache_timeout=0), name='schema-redoc'),
]

For more details about documentation go to the website Link

Step-9: Unit testing

Go to tests.py in "catapp" and implement the testing.
For running the tests.py write python manage.py test