Installation

Installing from PyPI is as easy as doing:

pip install django-google-api

Intigration

django-google-api is a library to use Google API with Django

INSTALLED_APPS = [
   ...
   'django_google.apps.DjangoGoogleConfig',
]

GOOGLE_CLIENT_SECRET_FILE = os.path.join(BASE_DIR, 'credentials.json')
GOOGLE_AUTH_SCOPES = [
    'https://www.googleapis.com/auth/userinfo.email',
    'https://www.googleapis.com/auth/userinfo.profile',
]

GOOGLE_CLIENT_ID = "xxxxxxxxxxxx-xxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com"

Usage:

execute commands

python manage.py makemigrations
python manage.py migrate

Create Views in views.py

from django.shortcuts import reverse, redirect, render
from django_google.flow import DjangoFlow,CLIENT_SECRET_FILE, SCOPES
from django.http.response import JsonResponse
from django.contrib.auth import get_user_model
from django.conf import settings
from django_google.models import GoogleAuth
User = get_user_model()

flow = DjangoFlow.from_client_secrets_file(client_secrets_file=CLIENT_SECRET_FILE, scopes=SCOPES)

# Auto Redirect to Google Authentication URL (Using Without Javascript)
def oAuthView(request):
        callback_url=reverse("oauth2callback") # callback Url (oAuth2CallBackView URL)
        return redirect(flow.get_auth_url(request, callback_url=callback_url))

# Google Authentication Call Back VIEW (Using Without Javascript)
def oAuth2CallBackView(request):
    success_url = "/dashboard/"  # redirection URL on Success reverse() can b use here
    creds = flow.get_credentails_from_response_url(response_url=request.build_absolute_uri())
    userinfo = flow.get_userinfo(creds=creds)
    try:
        user = User.objects.get(email=userinfo['email'])
    except User.DoesNotExist:
        user = User.objects.create(email=userinfo['email'],
                                           username=userinfo['email'],
                                           first_name=userinfo['given_name'],
                                           last_name=userinfo['family_name']
                                       )
    finally:
        try:
            gauth = GoogleAuth.objects.get(user=user)
        except GoogleAuth.DoesNotExist:
            gauth = GoogleAuth.objects.create(user=user, creds=creds)

    # Return Response as you want or Redirect to some URL

def oAuthJavascriptView(request):
    if request.is_ajax():
        if request.method == "POST":
            code = request.POST.get('code')
            flow = DjangoFlow.from_client_secrets_file(client_secrets_file=CLIENT_SECRET_FILE, scopes=SCOPES)
            creds = flow.get_credentials_from_code(code=code, javascript_callback_url="https://example.org")
            userinfo = flow.get_userinfo(creds=creds)
            try:
                user = User.objects.get(email=userinfo['email'])
            except User.DoesNotExist:
                user = User.objects.create(email=userinfo['email'],
                                               username=userinfo['email'],
                                               first_name=userinfo['given_name'],
                                               last_name=userinfo['family_name']
                                           )
            finally:
                try:
                    gauth = GoogleAuth.objects.get(user=user)
                except GoogleAuth.DoesNotExist:
                    gauth = GoogleAuth.objects.create(user=user, creds=creds)
            # return JSON Response with Status Code of 200 for success and 400 for errors
            return JsonResponse({}, status=200)

    else:
        context = {
            "client_id": getattr(settings, 'GOOGLE_CLIENT_ID', None),
            "scopes": " ".join(SCOPES)
        }
        # Render HTML page that havs Google Authentication Page with Javasccript
        return render(request, 'login.html', context)

Create Views in urls.py

from django.urls import path
from .views import oAuthView, oAuth2CallBackView, oAuthJavascriptView

urlpatterns = [
    path('', oAuthJavascriptView, name="login"),
    path('auth/', oAuthView, name="auth"),
    path('oauth2callback/', oAuth2CallBackView, name="oauth2callback"),
]

login.html file create Button of your own choice for google auth

<script src="https://apis.google.com/js/api:client.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-cookie/1.4.1/jquery.cookie.min.js"></script>
<button id="g-auth-btn">Sign in with <b>Google</b></button>
<script>
function startApp() {
    gapi.load('auth2', function(){
        auth2 = gapi.auth2.init({
            client_id: '{{ client_id }}',
            cookiepolicy: 'single_host_origin',
        });
    });
}

$(document).on("click", "#g-auth-btn", ()=>{
    auth2.grantOfflineAccess({
        prompt:"consent",
        scope: '{{ scopes }}'
    }).then((signInCallback)=>{
        $.ajax({
            type:'post',
            data:signInCallback,
            cache: false,
            headers: {"X-CSRFToken": $.cookie('csrftoken')},
            success: function (response) {
                console.log(response);
                if(!!response.redirect){
                    window.location = response.redirect
                }
            },
            error: function (error) {
                console.log(error);
                if(!!error.responseJSON.redirect){
                    window.location = error.responseJSON.redirect
                }
            }
        });
    });
});
startApp();
</script>