django启动问题---django.core.exceptions.ImproperlyConfigured: Requested setting INSTALLED_APPS

主体内容：
创建了一个pageApp，编写url和model以及views

urls.py
from django.urls import path
from pageApp import views
app_name = 'pageApp'

urlpatterns = [
    path("index/", views.index, name="index"),
]


models.py
from django.db import models
# Create your models here.
class Book(models.Model):
    title = models.CharField(max_length=128)
    price = models.DecimalField(decimal_places=2, max_digits=8)

    def __str__(self):
        return "Book：" + self.title


views.py
from django.http import HttpResponse
from pageApp.models import Book
# Create your views here.

def index(request):
    book_list = []
    for i in range(100):
        book = Book(title='book_%s'%i, price=i*i)
        # Book.objects.create(book)  # 每次插入都会访问数据库，数据量大时候会导致数据访问频繁，使用bulk_create
        book_list.append(book)
    Book.objects.bulk_create((book_list))
    return HttpResponse("ok")

全部代码如上所示，我们在views中导入的是from pageApp.models import Book。按照当前路径导包是不存在问题的，但是我们执行时候提示如下：（这个问题没有解决掉）

Traceback (most recent call last):
 File "C:/mysite/pageapp/views.py", line 4, in <module>
    from pageApp.models import Book
  File "C:\mysite\pageApp\models.py", line 4, in <module>
    class Book(models.Model):
  File "C:\mysite\env\lib\site-packages\django\db\models\base.py", line 129, in __new__
    app_config = apps.get_containing_app_config(module)
  File "C:\mysite\env\lib\site-packages\django\apps\registry.py", line 260, in get_containing_app_config
    self.check_apps_ready()
  File "C:\mysite\env\lib\site-packages\django\apps\registry.py", line 137, in check_apps_ready
    settings.INSTALLED_APPS
  File "C:\mysite\env\lib\site-packages\django\conf\__init__.py", line 102, in __getattr__
    self._setup(name)
  File "C:\mysite\env\lib\site-packages\django\conf\__init__.py", line 82, in _setup
    raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: Requested setting INSTALLED_APPS, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.

出现上述问题之后我重新导包如下：from .models import Book。之后提示变成如下所示，很明显根据现在框架结构这导包也是没问题。

Traceback (most recent call last):
  File "C:/mysite/pageapp/views.py", line 3, in <module>
    from .models import Book
ImportError: attempted relative import with no known parent package

最后最后，我看到自己执行条件下如下所以，它不是执行框架，而是当前views文件。所以框架启动不起来。
​

解决办法：
将启动条件改成框架即可。
​