[Answer]-List_display in admin behave nothing

Are you sure it’s not working correctly? list_display is supposed to take a tuple/list of fields and then display those fields as columns of the main table like in the picture shown below taken from the django admin documentation, where each entry in the main table has a username, email address, first name, last name, staff status. This would be created by

 list_display = ['username', 'email', 'first_name', 'last_name', 'is_staff']

in a ModelAdmin for the built in User model (taken from django.contrib.auth.models). The side-column on the right side (with the label “Filter”) is populated only when you define fields under list_filter.

Note if you only defined one field, and your model has a __unicode__ function that returns the username, you will not see a significant difference with just adding list_display = ('username',). I suggest you try list_display = ('username', 'first_name',). In this case, for every SignUp you will see two columns in the main table — one with the username and one with the first_name.

EDIT

You have two errors.

First, you don’t seem to have created any SignUp objects anywhere. Before the admin change list will display any entries, you must create some entries.

Second, your __unicode__ method of your SignUp model refers to non-existent fields (self.user is never defined — in your SignUp class you used username = models.OneToOneField(User)
, hence you refer to it as username) and furthermore it doesn’t return a unicode string as required.

Try:

def __unicode__(self):
    if self.username:
        return unicode(self.username)

then create some SignUp and then it will work. Again, the list_display part was working perfectly.