On Sat, May 18, 2013 at 10:22 PM, Dave Angel <da...@davea.name> wrote: > The pub_date is probably an instance attribute of either the Poll class or > the models.Model class. It should probably be defined in the appropriate > __init__ method. In any case it's not a method attribute.
Django uses function attributes as metadata. The names "boolean" and "short_description" are self-documenting. "admin_order_field" is explained here: https://docs.djangoproject.com/en/dev/ref/contrib/admin/ #django.contrib.admin.ModelAdmin.list_display Usually, elements of list_display that aren’t actual database fields can’t be used in sorting (because Django does all the sorting at the database level). However, if an element of list_display represents a certain database field, you can indicate this fact by setting the admin_order_field attribute of the item. The Poll model is part of the tutorial, "Writing your first Django app": https://docs.djangoproject.com/en/1.5/intro The function attributes are added in "Customize the admin change list", in part 2. > Perhaps you didn't realize that a function can have attributes, and that > they can be added to the function at any time after the function is created. > Being a method doesn't change that. In a class definition, from a conceptual point of view, you're adding a 'method'. But technically it's a function object. When accessed as an attribute, the function's __get__ descriptor is used to create a method on the fly. The instancemethod type has a custom __getattribute__ that first checks the method object's attributes such as __self__. If the lookup on the method object fails, it proxies the __getattribute__ of the wrapped __func__. For example: class Spam(object): def __repr__(self): return 'eggs' >>> meth = Spam().__repr__ >>> type(meth) <type 'instancemethod'> >>> meth.__self__ eggs A method doesn't have a __dict__ for setting dynamic attributes: >>> meth.boolean = False Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'instancemethod' object has no attribute 'boolean' But you can set attributes on the underlying function object: >>> type(meth.__func__) <type 'function'> >>> meth.__func__.boolean = False The method will proxy them: >>> meth.boolean False But not for assignment: >>> meth.boolean = True Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'instancemethod' object has no attribute 'boolean' _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
