old_contents: from django.views.generic import View
  from django.shortcuts import render, redirect
  from django.core.urlresolvers import reverse
  from django.contrib.auth import login, authenticate
  from django.contrib import messages
  
  
  class LogInView(View):
  
      def get(self, request):
          if request.GET.get('next', ''):
              messages.add_message(
                      request,
                      messages.WARNING,
                      "로그인을 해야 이용하실 수 있는 서비스입니다."
                      )
  
          return render(
                  request,
                  'users/login.html',
                  context={}
                  )
  
      def post(self, request):
  
          received_id = request.POST.get("username")
          received_pw = request.POST.get("password")
  
          # authenticate은 기존 user 테이블에 존재하는
          # 데이터와 일치하는지 확인
          user = authenticate(
                  username=received_id,
                  password=received_pw,
                  )
          if user:
              login(request, user)
              return redirect(
                      reverse("home")
                      )
          return redirect(
                  reverse("log_in")
                  )
  
new_contents: from django.views.generic import View
  from django.shortcuts import render, redirect
  from django.core.urlresolvers import reverse
  from django.contrib.auth import login, authenticate
  from django.contrib import messages
  
  
  class LogInView(View):
  
      def get(self, request):
          if request.GET.get('next', ''):
              messages.add_message(
                      request,
                      messages.WARNING,
                      "로그인을 해야 이용하실 수 있는 서비스입니다."
                      )
  
          return render(
                  request,
                  'users/login.html',
                  context={}
                  )
  
      def post(self, request):
  
          received_id = request.POST.get("username")
          received_pw = request.POST.get("password")
  
          # authenticate은 기존 user 테이블에 존재하는
          # 데이터와 일치하는지 확인
          user = authenticate(
                  username=received_id,
                  password=received_pw,
                  )
          if user:
              login(request, user)
              return redirect(
                      reverse("home")
                      )
  
          messages.add_message(
                  request,
                  messages.WARNING,
                  "존재하지 않는 회원정보입니다."
                  )
          return redirect(
                  reverse("log_in")
                  )
  
subject: update : if username not in database messages throw