python app.urls. Module not found

"""url(r'^', include('app.urls', namespace="app")),"""注释掉
    url(r'^', app.views.about, name='about1'),默认页面换成另一张。

pyinstaller和runserver运行时缺少模块的解决办法：
in urls.py加入
import django.contrib.sessions.models
import django.contrib.sessions.apps
import django.contrib.sessions
import django.contrib.sessions.middleware
import django.contrib.sessions.serializers
import django.template.loaders