In this article we will see how to create an API.

what is rest API?

REST (Representational State Transfer) API is a software architectural style that defines a set of constraints to be used for creating Web APIs. It is based on the following principles:

1. Client-server architecture: The client and server are separated, allowing them to evolve independently.

2. Statelessness: The server does not store any state about the client sessions in the form of cookies, sessions, or similar mechanisms.

3. Cacheability: The server indicates to the client whether a response can be cached or not, allowing the client to use a cached copy of the response if available.

4. Layered system: The server can be composed of multiple layers (e.g., load balancers, caches, application servers) without the client being aware of it.

5. Code on demand (optional): The server can include executable code in its responses, which the client can execute.

REST APIs are typically built using HTTP, and support the following HTTP methods:

• GET: Used to retrieve a resource.
• POST: Used to create a new resource.
• PUT: Used to update an existing resource.
• DELETE: Used to delete a resource.

REST APIs are used in modern web and mobile applications to communicate with servers, retrieve data, and perform various operations. They are a convenient and flexible way to expose the functionality of a backend system to the client, and are typically implemented using a framework such as Django Rest Framework (DRF) or Flask-RESTful.

How you can create an API using Django Rest Framework (DRF):

1. Install Django and DRF:

   $ pip install django
   $ pip install djangorestframework

2. Create a new Django project

   $ django-admin startproject myproject
   

3. Create a new Django app:

   $ python manage.py startapp myapp
   

4. Add 'rest_framework' to INSTALLED_APPS in your project's settings.py file:

   INSTALLED_APPS = [
       ...
       'rest_framework',
   ]
   

5. Define your model in models.py. For example:

   from django.db import models
   
   class Person(models.Model):
       name = models.CharField(max_length=128)
       email = models.EmailField()
       phone = models.CharField(max_length=16)
   

6. Run the following command to create the database tables for your models:

   $ python manage.py makemigrations
   $ python manage.py migrate
   

7. Create a serializer class in serializers.py to convert your model instances into JSON format:

   from rest_framework import serializers
   from .models import Person
   
   class PersonSerializer(serializers.ModelSerializer):
       class Meta:
           model = Person
           fields = ['id', 'name', 'email', 'phone']
   

8. Create a view in views.py to handle HTTP requests:

   from django.shortcuts import render
   from rest_framework import viewsets
   from .models import Person
   from .serializers import PersonSerializer
   
   class PersonViewSet(viewsets.ModelViewSet):
       queryset = Person.objects.all()
       serializer_class = PersonSerializer
   

9. Define the URL patterns in urls.py:

   from django.urls import include, path
   from rest_framework import routers
   from . import views
   
   router = routers.DefaultRouter()
   router.register(r'persons', views.PersonViewSet)
   
   urlpatterns = [
       path('', include(router.urls)),
   ]
   

10. Start the development server:

    $ python manage.py runserver
    

Now you can use HTTP requests to interact with your API at http://127.0.0.1:8000/persons/.

For example, you can use the following command to send a GET request to retrieve a list of all persons:

$ curl -X GET http://127.0.0.1:8000/persons/

You can also use the following command to send a POST request to create a new person:

$ curl -X POST -H "Content-Type: application/json" -d '{"name": "John Smith", "email": "john@example.com", "phone": "555-555-5555"}' http://127.0.0.1:8000/persons/

You can use postman for testing this API

You can check this course also Building APIs with Django and Dajngo rest framework

I hope this helps! If you have any problems you can comments