Step by Step create Simple API using python-django

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In this tutorial, we will learn how to create REST API. We will create 4 types of REST API.

GET
POST
PUT
DELETE

Start a project

create new project in PyCharm

Figure 1

Figure 2

Figure 3

Install Django

Go to Python Terminal and write following command and hit enter to install Django to your project.

Figure 4

python -m pip install Django

To check if Django is installed properly, go to Python console and write following code:

import django

print(django.get_version()

Figure 5

Showing version is 3.0.3

That means, Django installed successfully.

Create new project

Now need to create a project. Django always offer you to create a project at first and then you can create one or multiple app under the project. Write following command and hit enter at the terminal to create project.

django-admin startproject studentproject

After giving the command, you will see new project has been created in project tree.

Figure 6

Now go to your project. Hit the command:

Cd studentproject

Figure 7

Create app

Now create an app inside the project. Hit this command:

Terminal:> python manage.py startapp basicinfoapp

After giving the command, you will see an app name as basicinfoapp has been created in project inside.

Figure 8

Now you need to install app on project settings.

For that, go to studentproject > settings

Find the

INSTALLED_APP

tag

Figure 9

Edit the installed app configuration.

Add the app name you just created.

Figure 10

Create Model

Now create a model. Go to basicinfoapp folder.
Open the models.py file

Write following lines into the editor

from

django.db

import

models

# Create your models here.

class

Student(models.Model):

student_id = models.CharField(max_length=100)

student_name = models.CharField(max_length=100)

department = models.CharField(max_length=100)

contact_no = models.CharField(max_length=15)

def

__str__(self):

return

self.student_id

Figure 11

Migrate model to db

Now need to migrate the model into database. Write following command and hit enter.

python manage.py makemigrations basicinfoapp

Figure 12

Now type this command for migrate the project.

python manage.py migrate

Figure 13

Install rest framework

Now install rest framework. Go to terminal and hit this command:

pip install djangorestframework

Figure 14

After installing the package, you will see output

Create Serializer

Create serializers.py File in basicinfoapp folder.

Add following code:

from

rest_framework

import

serializers

from

.models

import

Student

class

employeeSerializers(serializers.ModelSerializer):

class

Meta:

model = Student

fields = [

“student_id”

,

“student_name”

,

“department”

,

“contact_no”

]

Figure 15

Create urls.py

Create new file as urls.py in basicinfoapp folder and add following package.

from

django.contrib

import

admin

from

django.urls

import

path

from

django.conf.urls

import

url

from

.

import

views

Figure 16

Create GET API to view list

Add following package in views.py file

from

django.shortcuts

import

render

from

django.http

import

Http404, HttpResponse

from

rest_framework.renderers

import

JSONRenderer

from

rest_framework.views

import

APIView

from

rest_framework.decorators

import

api_view

from

rest_framework.response

import

Response

from

rest_framework

import

status

from

django.http

import

JsonResponse

from

django.core

import

serializers

from

django.conf

import

settings

from

rest_framework

import

viewsets

from

django.views.decorators.csrf

import

csrf_exempt

from

rest_framework.decorators

import

api_view, renderer_classes

from

.serializers

import

studentSerializers

from

rest_framework.decorators

import

action

from

.models

import

Student

import

json

Now create a function to view student data:

class

StudentViewSet(viewsets.ModelViewSet):

@api_view([

‘GET’

, ])

def

studentList(self):

queryset = Student.objects.all()

serializer = studentSerializers(queryset, many=

True

,)

return

JsonResponse(serializer.data, safe=

False

)

Figure 17

Edit urls.py in basicinfoapp folder and configure URL:

from

django.contrib

import

admin

from

django.urls

import

path

from

django.conf.urls

import

url

from

.

import

views

urlpatterns = [

path(

‘list’

, views.StudentViewSet.studentList, name=

‘studentList’

),

]

Figure 18

Now go to studentproject > urls.py file.

Add following highlights:

Figure 19

Now write this command and hit enter to start py server:

python manage.py runserver

Figure 20

Now py server is running the localhost. Navigate your app url and see list data.
Hit this URL to any Rest Client like postman or RestLET or browser

URL

:

http://127.0.0.1:8000/student/list

Figure 21

No data is found in list. Already you created GET API to view the list. Now it’s time to add some data. You need to create POST API to add some data to view on list. We will create POST API later. Before that, lets login with the root user to Django admin portal and add some data. Let’s go.

Create Admin User

To create admin user, hit following command in terminal:

python manage.py createsuperuser

Then system will prompt you to give name of super admin user

I have given the super user name as ‘admin’

Now the system will prompt you to give email address

I have given the email as ‘admin@localhost.com’

Now the system will prompt you to give password

I have given the password as ‘123456’

I have confirmed the password again

Now system will alert that the password is easy. If I want to keep this password. I input ‘y’ for confirmation.

Now system creates superuser for me.

Figure 22

Now go to basicinfoapp folder and open admin.py file

Add following code:

from

django.contrib

import

admin

from

.models

import

Student

# Register your models here.

admin.site.register(Student)

Figure 23

Now start the py server again

Terminal:> python manage.py runserver

and navigate the URL:

http://127.0.0.1:8000/admin

Figure 24

Input the username and password you just created and login the admin portal.
You will see the model name in admin dashboard you created.

Figure 25

Click on the model name showing on admin portal. You will see a portal to add student.

Figure 26

Now click on “Add student” button and input data into admin portal

Figure 27

Figure 28

Now hit the following URL into any rest client like RESTClient or postman and see your inserted data is showing in json list

Figure 29

Create POST API to add data

Let’s create POST API to add data without admin portal.
Go to basic info app and open views.py file
Add following code in code edit window:

@api_view([

‘POST’

, ])

def

add_student(request):

if

request.method ==

“POST”

:

json_body = json.loads(request.body)

student_id = json_body[

‘student_id’

]
student_name = json_body[

‘student_name’

]
department = json_body[

‘department’

]
contact_no = json_body[

‘contact_no’

]

student = Student(student_id=student_id, student_name=student_name, department=department,contact_no=contact_no)

try

:

if

Student.objects.filter(student_id=student_id).exists():

response = json.dumps({

‘Status’

:

‘Student already exists’

})

else

:

student.save()

response = json.dumps({

‘Status’

:

‘Student added successfully’

})

except

ValueError

as

e:

response = json.dumps({

‘Status’

:

‘Student added failed’

})

# return JsonResponse(e.args[0], status.HTTP_400_BAD_REQUEST,safe=False)

return

HttpResponse(response, content_type=

“text/json”

)

Figure 30

Now open basicinfoapp > urls.py file and add this line:

path(

‘add’

, views.StudentViewSet.add_student, name=

‘add_student’

),

Figure 31

Now hit the command in terminal:

Terminal:> Python manage.py runserver

Now open any client app like postman/RestLET and set the parameters as:

URL

:

http://127.0.0.1:8000/student/add

Method

: POST

Body

: {

“student_id”:”103″,

“student_name”:”salman”,

“department”:”CSE”,

“contact_no”:”01602020110″

}

Figure 32

Create GET API to get data against Id

Now we will create a GET API to get information for a selected student Id. Let’s go.
Open views.py file
Add this code.

@api_view([

‘GET’

, ])

def

get_student(request, student_id):

try

:

student = Student.objects.get(student_id=student_id)

response = json.dumps({

‘student_id’

: student.student_id,

‘student_name’

: student.student_name,

‘department’

: student.department

,

‘contact_no’

: student.contact_no})

except

:

response = json.dumps({

‘Error’

:

‘No student found’

})

return

HttpResponse(response, content_type=

“text/json”

)

Figure 33

Add this line to urls.py

path(

‘show/<str:student_id>’

, views.StudentViewSet.get_student, name=

‘get_student’

),

Figure 34

Hit the URL to the browser/Postman/RestClient

http://127.0.0.1:8000/student/show/<student_id

> //pattern

http://127.0.0.1:8000/student/show/101

//student id

Figure 35

Create PUT API for data update

Now we will create PUT API for Update
Go to basicinfoapp > views.py
Add following lines

@api_view([

‘PUT’

, ])

def

update_student(request, student_id):

try

:

student = Student.objects.get(student_id=student_id)

serializer = studentSerializers(student, data=request.data)

data = {}

if

(serializer.is_valid()):

serializer.save()

data[

“success”

] =

“Update successful”

return

Response(data=data)

except

:

response = json.dumps({

‘Status’

:

‘No student found’

})

return

HttpResponse(response, content_type=

“text/json”

)

Figure 36

Then Add line in urls.py file

path(

‘update/<str:student_id>’

, views.StudentViewSet.update_student, name=

‘update_student’

),

Figure 37

Run Py server from terminal and go to REST API Client

Terminal:> Python manage.py runserver

Set the parameters as:

URL

: http://127.0.0.1:8000/student/update/103

Method

: PUT

Body

: {

“student_id”:”103″,

“student_name”:”Salman Rahman”,

“department”:”CSE”,

“contact_no”:”01602020110″

}

Output: Updated successfully

Figure 38

Now you can check by calling your get data API to see the changes

Figure 39

Changes applied. So, update work successfully.

Create DELETE API to delete data

Now we will create DELETE API to delete a data
Open basicinfoapp/views.py file
Add following code.

@api_view([

‘DELETE’

, ])

def

delete_student(request, student_id):

try

:

student = Student.objects.get(student_id=student_id)

student.delete()

response = json.dumps({

‘Status’

:

‘Deleted’

})

except

:

response = json.dumps({

‘Status’

:

‘No student found’

})

return

HttpResponse(response, content_type=

“text/json”

)

Figure 40

Add this line to urls.py file.

path(

‘delete/<str:student_id>’

, views.StudentViewSet.delete_student, name=

‘delete_student’

),

Figure 41

Now hit the URL to any Rest Client. Set parameters as:

URL

:

http://127.0.0.1:8000/student/delete/102

Method

: DELETE

to the REST Client and you will get output as “Deleted”

Figure 42