Django or Django Rest Framework

I have made a certain app in Django, and I know that Django Rest Framework is used for building APIs. However, when I started to read about Django Rest Framework on their website, I noticed that each and every thing in API Guide(like request, response, views etc.) claims it is superior to Django (request, response, views etc.).

The thing I am not understanding is whether these APIs will replace my existing Django models, views etc. or how can I use them differently in my existing Django code?

I am quite familiar with Django, but not able to understand exactly what Django Rest Framework is even after spending some time on it. (I know it is used for APIs.) Also, do I actually need an API? My app is able to send data to the server without an API, so in what case would I need an API?

Django Rest Framework makes it easy to use your Django Server as an REST API.

REST stands for "representational state transfer" and API stands for application programming interface.

You can build a restful api using regular Django, but it will be very tedious. DRF makes everything easy. For comparison, here is simple GET-view using just regular Django, and one using Django Rest Framework:

Regular:

from django.core.serializers import serialize
from django.http import HttpResponse


class SerializedListView(View):
    def get(self, request, *args, **kwargs):
        qs = MyObj.objects.all()
        json_data = serialize("json", qs, fields=('my_field', 'my_other_field'))
        return HttpResponse(json_data, content_type='application/json')

And with DRF this becomes:

from rest_framework import generics


class MyObjListCreateAPIView(generics.ListCreateAPIView):
    permission_classes = [permissions.IsAuthenticatedOrReadOnly]
    serializer_class = MyObjSerializer

Note that with DRF you easily have list and create views as well as authentication.

Whether you need an api depends on what you want to do. For example, if you want to access everything in your Django models from a mobile device AND a web-app, you would want to use DRF.

Why? Consider the case that you are developing an iOS app that users can sign into and you want to use Django as your backend. If you also want to have a website that they can use to change around their app's profile information (say, update their email address or upload a picture), you would need a way to share the information in your Django models with both a website and the iOS device. How can this be done? By giving the user the ability to create/read/update/delete data by simply telling it a url to go to. Now, if you want to access information from the model you can do it from multiple devices, since any device can visit a url.

However, if you're just building a simple webapp/webpage and keep it all in one place, you can just use straight Django.

Side note: it's a pretty popular opinion that you should try to separate your frontend from your backend as much as possible. In this case, if you want to use some frontend development framework like React, Angular, or Vue, it's gonna get messy trying to include all those resources in the Django template pages even if you only want a simple web app/web page. In this case, you would use DRF to set up your backend, and just hit the urls from the frontend using a tool like axios. In this scenario, your frontend would likely be hosted on something like Node.

Again, what you decide to use really just depends on what you want out of your app/site and how comfortable you are with each tool.

The basic purpose of DRF is to provide APIs. APIs are the touch point in an app. Imagine a project where you have a Django wizard and someone on your team is a JavaScript expert and you want to develop mobile app. The JavaScript expert talks about web elements and threading and the Django expert talks templates and ORM, now what? API is your answer. Let Django wiz give APIs and JSON and let JavaScript wiz do his front end magic. Simplest answer I can think of.

In simple words,

Django : It provide features for standard web app

Django Rest Framework: It provide features to build standard REST API.

the old school used Jinja2 with html5, css3, but this became inconvenient when Single Page Applications became popular.API helps to provide information more convenient for the frontend programmer. You no longer work with the frontend. The API is convenient when developing as Web applications and when developing applications for the phone.

Let's sum up,

Django :

Tightly coupled with Django Templates.

Django Rest Framework :

Open for building views of my own choices with REST APIs.

Here is a link which might give you some insights on what you are looking for. This explains how a django app can be converted into Django Rest Service, and it also explains what a REST Service actually is

https://opensourceforu.com/2017/11/converting-django-app-rest-api/

Simply saying: with just Django you can create server side rendered websites; and with DRF you can create SPAs with a vuejs or react frontend part.

1. Do you actually need Api? It depends on your requirement and resources. If you only need a web application then django provides everything you require to develop a web application. If you need to develop a mobile application that will communicate with a backend server then you will have to implement Api. If you have remote iot devices that needs to publish its data to your server, you will need Api. If you are good at frontend app development, mobile app development, and iot app development or you have resources to have separate team for frontend, backend, mobile and iot app development then it is good design to separate backend and frontend applications. To achieve this separation, your backend will be api based and your frontend, mobile and iot app will communicate with your backend using your backend api. With this design, any changes in backend will have minimal impact on your other apps.

2. Will these APIs replace your existing Django models? Ideally it should not but I am not sure if using drf will change your django models. I have not used drf to implement api. But if you just use django to implement your api, it will definitely will not change your models. You just need to define your api urls and api views.

3. Do you require external packages like drf to implement api endpoint in Django? No. You can easily implement Api endpoints using pure Django framework.

4. A simple way to implement api using pure Django.

   Define your api url -

   urlpatterns = [   
       path('get_all_user/',UserApiView.as_view(),name='get_all_user'), 
   ]
   

   Define your view

   @method_decorator(csrf_exempt,name='dispatch') 
   class UserApiView(View):
   
       def post(self, request):
           response_data = {}
           json_data = json.loads(request.body)
           response_data['user'] = YourMethodToGetModelData(json_data)
           return JsonResponse(response_data)
   

You can use django to build a complete web application, then what is the need of api?

Let's take a example for suppose at first you build a website for your startup using django. Your site grew popular, and for easier access in Android you thought of building a mobile application. Then are you going to maintain a separate database? Nope, because not only it's difficult to maintain, but migrating the old data is also a headache. So here what django rest framework comes into play. You can set up apis to be used by your Android application, hence have to maintain a single database against multiple apps.