old_contents: from django.shortcuts import render
  
  from django.http import HttpResponse
  
  def main_view(request):
      return HttpResponse("Hello, World! This is main page!")
  
new_contents: from django.shortcuts import render
  
  from django.http import HttpResponse
  
  def main_view(request):
      return HttpResponse("Hello, World! This is main page!")
  
  def register_view(reguest):
      return HttpResponse("Register View")
  
  def login_view(reguest):
      return HttpResponse("Login View")
  
  def logout_view(reguest):
      return HttpResponse("Logout View")
  
subject: add base for register/login/logout views