django 创建应用程序时，定义模型时models.py报错

suishoufang

django 创建应用程序，定义模型时候，models.py报错，请教下大家这是什么原因，搞了好久没搞懂


代码：
from django.db import models

# Create your models here. 定义模型

class Topic(models.Model):
        """用户学习的主题"""
        text = models.CharField(max_length = 200)
        data_added = models.DateTimeField(auto_now_add = True)

        def __str__(self):
                """返回模型的字符串表示"""
                return self.text


报错：
Python 3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 14:57:15) [MSC v.1915 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
>>>
============== RESTART: F:\python test\learning_logs\models.py ==============
Traceback (most recent call last):
  File "F:\python test\learning_logs\models.py", line 5, in <module>
    class Topic(models.Model):
  File "D:\Python\lib\site-packages\django\db\models\base.py", line 87, in __new__
    app_config = apps.get_containing_app_config(module)
  File "D:\Python\lib\site-packages\django\apps\registry.py", line 249, in get_containing_app_config
    self.check_apps_ready()
  File "D:\Python\lib\site-packages\django\apps\registry.py", line 131, in check_apps_ready
    settings.INSTALLED_APPS
  File "D:\Python\lib\site-packages\django\conf\__init__.py", line 57, in __getattr__
    self._setup(name)
  File "D:\Python\lib\site-packages\django\conf\__init__.py", line 42, in _setup
    % (desc, ENVIRONMENT_VARIABLE))
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.

求助求助，先感谢大家

wongyusing

max_length = 200和auto_now_add = True
我没记错的话中间不能有空格
要改成下面这种
auto_now_add=True

还有，你的缩进好像有问题
给你看个例子吧

1. class Blog(models.Model):
   
2.     title = models.CharField(verbose_name="标题",max_length=50)
   
3.     body = models.TextField(verbose_name="内容")
   
4.     author = models.CharField(verbose_name="作者",max_length=50,default='sing')
   
5.     created_time = models.DateTimeField(auto_now_add=True,verbose_name='创建时间')
   
6.     update_time = models.DateTimeField(auto_now=True,verbose_name='修改时间')
   
7.     slug = models.SlugField(verbose_name="索引后缀",unique=True)
   
8. 
   
9.     class Meta:
   
10.         verbose_name = '文章'
    
11.         verbose_name_plural = verbose_name
    
12.         ordering = ['-created_time']
    
13. 
    
14.     # 使对象在后台显示更友善
    
15.     def __str__(self):
    
16.         return self.title

复制代码