from django.db import modelsclass Blog(models.Model):    name = models.CharField(max_length=100)    tagline = models.TextField()     # On Python 3: def __str__(self):    def __unicode__(self):        return self.name class Author(models.Model):    name = models.CharField(max_length=50)    email = models.EmailField()     # On Python 3: def __str__(self):    def __unicode__(self):        return self.name class Entry(models.Model):    blog = models.ForeignKey(Blog)    headline = models.CharField(max_length=255)    body_text = models.TextField()    pub_date = models.DateField()    mod_date = models.DateField()    authors = models.ManyToManyField(Author)    n_comments = models.IntegerField()    n_pingbacks = models.IntegerField()    rating = models.IntegerField()     # On Python 3: def __str__(self):    def __unicode__(self):        return self.headline

class MyUser(AbstractBaseUser):    ...    def has_perm(self, perm, obj=None):        if self.is_superuser:            return True        elif self.can_edit:            if perm=='myapp.add_entry':                return True            else:                return False        else:            return False

    def has_add_permission(self, request):        """        Returns True if the given request has permission to add an object.        Can be overridden by the user in subclasses.        """        opts = self.opts        codename = get_permission_codename('add', opts)        if request.user.can_edit:            return True        else:            return request.user.has_perm("%s.%s" % (opts.app_label, codename))

class EntryAdmin(admin.ModelAdmin):    list_display=(...)    search_fields=(...)    def get_readonly_fields(self,request,obj=None):        if not request.user.is_superuser and not request.user.can_edit:            return [f.name for f in self.model._meta.fields]        return self.readonly_fields

from django.db import modelsclass Blog(models.Model):    name = models.CharField(max_length=100)    tagline = models.TextField()    def save(self, *args, **kwargs):        do_something()        super(Blog, self).save(*args, **kwargs) # Call the "real" save() method.        do_something_else()

from django.db import modelsclass Blog(models.Model):    name = models.CharField(max_length=100)    tagline = models.TextField()    def save(self, *args, **kwargs):        if self.name == "Yoko Ono's blog":            return # Yoko shall never have her own blog!        else:            super(Blog, self).save(*args, **kwargs) # Call the "real" save() method.

from django.contrib import adminclass ArticleAdmin(admin.ModelAdmin):    def save_model(self, request, obj, form, change):        obj.user = request.user        obj.save()

from django.contrib import adminclass ArticleAdmin(admin.ModelAdmin):    def save_model(self, request, obj, form, change):        if change:            obj_old = self.model.objects.get(pk=obj.pk)        else:            obj_old = None        obj.user = request.user        obj.save()

class MyModelAdmin(admin.ModelAdmin):    def get_queryset(self, request):        qs = super(MyModelAdmin, self).get_queryset(request)        if request.user.is_superuser:            return qs        return qs.filter(author=request.user)

from datetime import datefrom django.contrib import adminfrom django.utils.translation import ugettext_lazy as _class DecadeBornListFilter(admin.SimpleListFilter):    # Human-readable title which will be displayed in the    # right admin sidebar just above the filter options.    title = _('decade born')    # Parameter for the filter that will be used in the URL query.    parameter_name = 'decade'    def lookups(self, request, model_admin):        """        Returns a list of tuples. The first element in each        tuple is the coded value for the option that will        appear in the URL query. The second element is the        human-readable name for the option that will appear        in the right sidebar.        """        return (            ('80s', _('in the eighties')),            ('90s', _('in the nineties')),        )    def queryset(self, request, queryset):        """        Returns the filtered queryset based on the value        PRovided in the query string and retrievable via        `self.value()`.        """        # Compare the requested value (either '80s' or '90s')        # to decide how to filter the queryset.        if self.value() == '80s':            return queryset.filter(birthday__gte=date(1980, 1, 1),                                    birthday__lte=date(1989, 12, 31))        if self.value() == '90s':            return queryset.filter(birthday__gte=date(1990, 1, 1),                                    birthday__lte=date(1999, 12, 31))class PersonAdmin(admin.ModelAdmin):    list_filter = (DecadeBornListFilter,)

class AuthDecadeBornListFilter(DecadeBornListFilter):    def lookups(self, request, model_admin):        if request.user.is_superuser:            return super(AuthDecadeBornListFilter,                self).lookups(request, model_admin)    def queryset(self, request, queryset):        if request.user.is_superuser:            return super(AuthDecadeBornListFilter,                self).queryset(request, queryset)

class AdvancedDecadeBornListFilter(DecadeBornListFilter):    def lookups(self, request, model_admin):        """        Only show the lookups if there actually is        anyone born in the corresponding decades.        """        qs = model_admin.get_queryset(request)        if qs.filter(birthday__gte=date(1980, 1, 1),                      birthday__lte=date(1989, 12, 31)).exists():            yield ('80s', _('in the eighties'))        if qs.filter(birthday__gte=date(1990, 1, 1),                      birthday__lte=date(1999, 12, 31)).exists():            yield ('90s', _('in the nineties'))

class PersonAdmin(admin.ModelAdmin):    list_display = ('name', 'age')    search_fields = ('name',)    def get_search_results(self, request, queryset, search_term):        queryset, use_distinct = super(PersonAdmin, self).get_search_results(request, queryset, search_term)        try:            search_term_as_int = int(search_term)        except ValueError:            pass        else:            queryset |= self.model.objects.filter(age=search_term_as_int)        return queryset, use_distinct

class MyModelAdmin(admin.ModelAdmin):    def formfield_for_foreignkey(self, db_field, request, **kwargs):        if db_field.name == "car":            kwargs["queryset"] = Car.objects.filter(owner=request.user)        return super(MyModelAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)