Django : Python : Models Base.py IndexError: list index out of range

This page has the solution to IndexError Django throws when you try to access the model API from a standalone script.

I tried to import the model class after setting the PYTHONPATH and DJANGO_SETTINGS_MODULE Environment Variables

>>> from models import Player

This is the error I got,

.....
  File "C:\Python27\lib\site-packages\django\db\models\base.py", line 52, in __new__
    kwargs = {"app_label": model_module.__name__.split('.')[-2]}
IndexError: list index out of range

After some googling and code search, the base.py expects the app name and its not available when you try to access the model API from a standalone script.

So you have to add the meta information APP name to all the model classes under the models.py. That will get rid of this error.

class xxx(models.Model):
    name = models.CharField(max_length=200)
    country = models.CharField(max_length=200)
    twitter_handle = models.CharField(max_length=100)
    followers = models.IntegerField('number of twitter followers')
    
    def __unicode__(self):
        return self.twitter_handle
    class Meta:
        app_label = 'appname'
    
class yyy(models.Model):
    xxx= models.ForeignKey(xxx)
    conversation = models.CharField(max_length=10000)
    teaser = models.CharField(max_length=50)
    views = models.IntegerField('popularity')
    likes = models.IntegerField()
    published_date = models.DateTimeField('date_published')
    
    def __unicode__(self):
        return self.teaser
    class Meta:
        app_label = 'appname'

ImportError: Could not import settings xxx.settings : Django : Python : Windows

Recently, I built an application using Django. I wanted to create a standalone script that used the My App’s model API to insert data into Database.

The Django Document says:

“If you’d rather not use manage.py, no problem. Just make sure mysiteandpollsare at the root level on the Python path (i.e., import mysiteandimport pollswork) and set theDJANGO_SETTINGS_MODULE environment variable tomysite.settings.”

I was little confused about those statements.

So what is PYTHONPATH? In general, it’s the collection of all searchable paths where python would search for modules that you might use in your programs.

Initially, I screwed up the environmental variables and this is the error that I got.

 

 

......self._wrapped = Settings(settings_module)
File "C:\Python27\lib\site-packages\django\conf\__init__.py", line 89, in __init__
raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'LearnPython.settings' (Is it on sys.path?): No module named LearnPython.settings

So this is what I did:
1) Set the PYTHONPATH environment variable to point to the directory of your django app.

PYTHONPATH = “C:\path\to\myapp\”

this is the path under which you’ll have the models.py

2) set the DJANGO_SETTINGS_MODULE environmental variable. This is the settings module that your app will use to determine the database user,password , host etc.

In my case I set DJANGO_SETTINGS_MODULE = “myapp.settings”

To confirm that everything worked, after setting the environmental variables , I logged into a new command prompt ,

C:\Users\xxx>python
Python 2.7.2 (default, Jun 12 2011, 14:24:46).....
32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> print os.environ['DJANGO_SETTINGS_MODULE']
cricketweet.settings
>>> from models import Player
>>>

So Now I can access the model classes from a stand alone app. Happy coding

Improperly Configured MySQL DB Module-Exception – Django – Windows 7

I had this error after I installed Django, created a project, modified the settings.py to use the MySQL database and while I tried to create the necessary tables in the MySQL by running the following command.

 python manage.py syncdb 

I got this exception

 .......

backend = load_backend(db['ENGINE'])
  File "c:\Python27\lib\site-packages\django\db\utils.py", line 33, in load_backend
    return import_module('.base', backend_name)
  File "c:\Python27\lib\site-packages\django\utils\importlib.py", line 35, in import_module
    __import__(name)
  File "c:\Python27\lib\site-packages\django\db\backends\mysql\base.py", line 14, in 
    raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named MySQLdb 

I was using Python 2.7 , so the solution was to use the MySQL Python connector. I downloaded it from here

After , I Installed the MySQL Python Connector, I created the MySQL database,(make sure you commit it) This seemed to work fine.

 $ python manage.py syncdb
Creating tables ...
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table auth_user_user_permissions
Creating table auth_user_groups
Creating table auth_user
Creating table auth_message
Creating table django_content_type
Creating table django_session
Creating table django_site

You just installed Django's auth system, which means you don't have any superusers defined.
Would you like to create one now? (yes/no): yes
Username (Leave blank to use 'test'):
E-mail address: test@gmail.com
Password:
Password (again):
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
No fixtures found. 

Hopefully this helps.