old_contents: # -*- coding: utf-8 -*-
  from django.contrib import admin
  from django.core.mail import send_mail, send_mass_mail
  from modeltranslation.admin import TranslationAdmin
  
  from .models import Registration, Option
  
  def send_bankpayment_alert_email(modeladmin, request, queryset):
      messages = []
      subject = u"PyCon APAC 2016 입금확인부탁드립니다. Please Check PyCon APAC 2016 payment"
      body = u"""
      안녕하세요. PyCon APAC 준비위원회입니다.
      현재 입금여부를 확인하였으나 입금이 되지 않았습니다.
      혹시나 다른 이름으로 입금하신분은 support@pycon.kr 로 메일 부탁드립니다.
      입금시한은 구매로부터 일주일입니다.
      감사합니다.
      """
      from_email = "support@pycon.kr"
      for obj in queryset:
          email = obj.email
          message = (subject, body, from_email, [email])
      send_mass_mail(messages, fail_silently=False)
  
  send_bankpayment_alert_email.short_description = "Send Bank Payment Email"
  
  class OptionAdmin(admin.ModelAdmin):
      list_display = ('name', 'is_active', 'price')
      list_editable = ('is_active',)
      ordering = ('id',)
  admin.site.register(Option, OptionAdmin)
  
  
  class RegistrationAdmin(admin.ModelAdmin):
      list_display = ('user', 'option', 'name', 'email', 'payment_method',
                      'payment_status', 'created', 'confirmed', 'canceled')
      list_editable = ('payment_status',)
      list_filter = ('option', 'payment_method', 'payment_status')
      search_fields = ('name', )
      readonly_fields = ('created', )
      ordering = ('id',)
      actions = (send_bankpayment_alert_email,)
  admin.site.register(Registration, RegistrationAdmin)
  
new_contents: # -*- coding: utf-8 -*-
  from django.contrib import admin
  from django.core.mail import send_mail, send_mass_mail
  from modeltranslation.admin import TranslationAdmin
  
  from .models import Registration, Option
  
  def send_bankpayment_alert_email(modeladmin, request, queryset):
      messages = []
      subject = u"PyCon APAC 2016 입금확인부탁드립니다. Please Check PyCon APAC 2016 payment"
      body = u"""
      안녕하세요. PyCon APAC 준비위원회입니다.
      현재 입금여부를 확인하였으나 입금이 되지 않았습니다.
      혹시나 다른 이름으로 입금하신분은 support@pycon.kr 로 메일 부탁드립니다.
      입금시한은 구매로부터 일주일입니다.
      감사합니다.
      """
      from_email = "pycon@pycon.kr"
      for obj in queryset:
          email = obj.email
          message = (subject, body, from_email, [email])
          messages.append(message)
      send_mass_mail(messages, fail_silently=False)
  
  send_bankpayment_alert_email.short_description = "Send Bank Payment Email"
  
  class OptionAdmin(admin.ModelAdmin):
      list_display = ('name', 'is_active', 'price')
      list_editable = ('is_active',)
      ordering = ('id',)
  admin.site.register(Option, OptionAdmin)
  
  
  class RegistrationAdmin(admin.ModelAdmin):
      list_display = ('user', 'option', 'name', 'email', 'payment_method',
                      'payment_status', 'created', 'confirmed', 'canceled')
      list_editable = ('payment_status',)
      list_filter = ('option', 'payment_method', 'payment_status')
      search_fields = ('name', )
      readonly_fields = ('created', )
      ordering = ('id',)
      actions = (send_bankpayment_alert_email,)
  admin.site.register(Registration, RegistrationAdmin)
  
subject: fix to send mass mail