Question

views.py

from registration.models import Registration
from django.core.context_processors import csrf
from registration import tasks
from django.shortcuts import render_to_response
def validate(request):
    state="notvalid"
    if request.method == 'POST':# If the form has been submitted...
        form = Registration(request.POST) # A form bound to the POST data
        state="notvalid"
        if form.is_valid(): 
            username = form.cleaned_data['username']
            first_name = form.cleaned_data['first_name']
            last_name = form.cleaned_data['last_name']
            email = form.cleaned_data['email']
            password = form.cleaned_data['password']
            from django.contrib.auth.models import User
            user = User.objects.create_user(username,email,password)
            user.first_name=first_name
            user.last_name=last_name        
            user.save() 
            state="added data"
        tasks.mail()
    else:
        form = Registration() # An unbound form

    return render_to_response('auth1.html', {
        'form': form,'state':state,
    })

tasks.py

from celery import task
import celery

@celery.task()
def mail():
    from django.core.mail import send_mail
    for x in range(10000000):
        print x
    return True

the task has to be performed parrelel without affecting the time of views response. I.e
in background it has to run mail function

but after database adding it hase to return render_to_response

Answer 1

Your call to trigger the mail task should be:

tasks.mail.delay()

Without the delay(), the task will run in the same process as the view, not in a Celery worker, and so the view function will block until mail is finished.

See http://docs.celeryproject.org/en/latest/django/first-steps-with-django.html#calling-our-task for more.