django、templatedoesnotexist 404エラーについて

Question

djangoを使ってwebアプリケーションを作ろうとしていて、ログイン機能を作っています。
ログイン処理実装にて参考にしたサイト：https://intellectual-curiosity.tokyo/2018/11/13/django%E3%81%AE%E3%83%AD%E3%82%B0%E3%82%A4%E3%83%B3%E5%87%A6%E7%90%86%E3%82%92%E5%AE%9F%E8%A3%85%E3%81%99%E3%82%8B%E6%96%B9%E6%B3%95%E2%91%A0/

実際に http://127.0.0.1:8000/accounts/login/ でリロードした際に、templatedoesnotexistのエラーが出ます。そもそもregistrationという記述はないのですが、どうしてこのようなエラーが出るのでしょうか。

発生している問題・エラーメッセージ

Internal Server Error: /accounts/login/
Traceback (most recent call last):
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/core/handlers/base.py", line 217, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/core/handlers/base.py", line 215, in _get_response
    response = response.render()
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/template/response.py", line 107, in render
    self.content = self.rendered_content
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/template/response.py", line 82, in rendered_content
    template = self.resolve_template(self.template_name)
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/template/response.py", line 64, in resolve_template
    return select_template(template, using=self.using)
  File "/Users/nishikawakyo/opt/anaconda3/envs/locket/lib/python3.7/site-packages/django/template/loader.py", line 53, in select_template
    raise TemplateDoesNotExist(', '.join(template_name_list), chain=chain)
django.template.exceptions.TemplateDoesNotExist: registration/login.html

該当のソースコード settings.py!

"""myblogapp URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import include, url
from django.contrib import admin
from django.conf.urls.static import static
from django.conf import settings
from posts import views

urlpatterns = [
    url(r'^posts/', include('posts.urls.index_urls')), 
    url(r'^posts/(?P<post_id>[0-9]+)/$', views.post_detail, name='post_detail'),
    url(r'^admin/', admin.site.urls),
    url(r'^about/', include("posts.urls.index_urls")),
    url(r'^geo/', include("posts.urls.geo_urls")),
    url(r'^accounts/', include("django.contrib.auth.urls")),#変更箇所
    # url(r'^accounts/', include("posts.urls")),
    # url(r'^post_new_post', views.post_new_post),
    # url(r'^login', views.login_user),
    # url(r'^registration', views.registation_user),
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

試したこと

settings.pyのos.path.join()~の箇所を再チェック

補足情報（FW/ツールのバージョンなど）

Answer 1

django.contrib.auth.views.LoginViewがregistration/login.htmlを使用するためです。

下記のようにテンプレートディレクトリを設定して、myblogapp/templates/registration/login.htmlファイルに、ユーザー名とパスワードを入力するテンプレートを作成してみてください。

# settings.py
TEMPLATES = [
    {
        ...,
        'DIRS': [os.path.join(BASE_DIR, 'templates'), ],
        ...,
    },
    ...
]