|Version 7 (modified by Boffbowsh, 10 years ago) (diff)|
Please feel free to share the things that tripped you up when you started with Django. We'll try to improve Django's error handling to catch such mistakes in the future.
URLconf include() misbehaving
You're trying to get your URLconf files to work, but getting cryptic errors about how there is no module 'index' (where 'index' is some function you are trying to assign as a view), or module 'foo' has no attribute 'urlpatterns'.
You may have tried to load your view files using include() in the URLconf file (in tutorial 3, this is myproject/settings/urls/main.py). The include() call assumes that the file it's loading is also a URLconf file.
Remove the include(). Just give the module and function name (e.g., 'myproject.apps.polls.views.polls.index') as a string, with no include() around it.
Blank object names
The automatic admin interface is showing nothing (or a single ) in the "Select [object_type] to change" view.
You may have forgotten to create a __repr__() function for your model. Django calls __repr__() to find out how to display objects in the admin interface.
Add a __repr__() function to all your models. Make it a habit so it becomes automatic.
Integer & NULLS
When you have a Field: current_zip = meta.IntegerField(maxlength=5,blank=True)
django will create a not nullable field in the DB. However leaving the field blank (in admin/web) django will try and insert a NULL value in the DB.
current_zip = meta.IntegerField(maxlength=5,null=True,blank=True)
Appending to a list in session doesn't work
If you have a list in your session, append operations don't get saved to the object.
Copy the list out of the session object, append to it, then copy it back in:
sessionlist = request.session['my_list'] sessionlist.append(new_object) request.session['my_list'] = sessionlist