. . .
from django.contrib.auth import authenticate, login, logout
. . .
def login_view(request):
username = request.POST['username']
    password = request.POST['password']
    user = authenticate(request, username=username, password=password)
    if user is not None:
        login(request, user)
        return redirect('index')

    context = {'message': 'Invalid Username/Password'}
    return render(request, 'peliculas/signin.html', context)
. . .