@csrf_exempt
def index(request):
    if ('a' in request.POST):
        a = int(request.POST['a'])
        b = int(request.POST['b'])
    else:
        a = 0
        b = 0
    return HttpResponse((text % (a, b, (a + b))))
@csrf_exempt
def index(request):
    if ('a' in request.POST):
        a = int(request.POST['a'])
        b = int(request.POST['b'])
    else:
        a = 0
        b = 0
    return HttpResponse((text % (a, b, (a + b))))