django: the value of list_display[4] refers to 'age', which is not a callable, etc

from django.contrib.auth.admin
import UserAdmin

class PersonInline(admin.StackedInline):
   ""
" Details a person in line. "
""
model = Person
can_delete = False
verbose_name_plural = 'person'

fields = ('username', 'email', 'first_name', 'last_name', 'age', 'city', 'state')

class UserAdmin(UserAdmin):
   inlines = [
      PersonInline
   ]

# Re - register UserAdmin
admin.site.unregister(User)
admin.site.register(User, UserAdmin)

ERRORS:
<class 'polls.admin.PersonAdmin'>: (admin.E108) The value of 'list_display[4]' refers to 'age', which is not a callable, an attribute of 'PersonAdmin', or an attribute or method on 'auth.User'.
   <class 'polls.admin.PersonAdmin'>:(admin.E108) The value of 'list_display[5]' refers to 'city', which is not a callable, an attribute of 'PersonAdmin', or an attribute or method on 'auth.User'.
      <class 'polls.admin.PersonAdmin'>: (admin.E108) The value of 'list_display[6]' refers to 'state', which is not a callable, an attribute of 'PersonAdmin', or an attribute or method on 'auth.User'.

class Person(models.Model):
   ""
" The model which defines a user of the application. Contains important
information like name, email, city / state, age, etc ""
"
user = models.OneToOneField(User, on_delete = models.CASCADE)
first_name = models.CharField(max_length = 200, null = True)
last_name = models.CharField(max_length = 200, null = True)
email = models.CharField(max_length = 200, null = True)
city = models.CharField(max_length = 200, null = True)
state = models.CharField(max_length = 200, null = True)
age = models.CharField(max_length = 50, null = True)

def create_account(request):
   #
function to allow a user to create their own account
if request.method == 'POST':
   # sets a new user and gives them a username
new_user = User(username = request.POST["username"],
   email = request.POST["email"],
   first_name = request.POST["first_name"],
   last_name = request.POST["last_name"],
   age = request.POST["age"],
   city = request.POST["city"],
   state = request.POST["state"]
)

# sets an encrypted password
new_user.set_password(request.POST["password"])
new_user.save()
# adds the new user to the database
Person.objects.create(user = new_user,
   first_name = str(request.POST.get("first_name")),
   last_name = str(request.POST.get("last_name")),
   email = str(request.POST.get("email")),
   age = str(request.POST.get("age")),
   city = str(request.POST.get("city")),
   state = str(request.POST.get("state"))
)
new_user.is_active = True
new_user.save()
return redirect('../')
else:
   return render(request, 'polls/create_account.html')

from django.contrib.auth.admin
import UserAdmin

class PersonInline(admin.StackedInline):
   ""
" Details a person in line. "
""
model = Person
can_delete = False
verbose_name_plural = 'person'

fields = ('username', 'email', 'first_name', 'last_name', 'age', 'city', 'state')

class UserAdmin(UserAdmin):
   inlines = [
      PersonInline
   ]

# Re - register UserAdmin
admin.site.unregister(User)
admin.site.register(User, UserAdmin)

from django.contrib.auth.admin
import UserAdmin

class PersonInline(admin.StackedInline):
   ""
" Details a person in line. "
""
model = Person
can_delete = False
verbose_name_plural = 'person'

fields = ('username', 'email', 'first_name', 'last_name', 'age', 'city', 'state')

class UserAdmin(UserAdmin):
   inlines = [
      PersonInline
   ]

# Re - register UserAdmin
admin.site.unregister(User)
admin.site.register(User, UserAdmin)

from django.contrib
import admin
from myapp.models
import Author

class AuthorAdmin(admin.ModelAdmin):
   pass
admin.site.register(Author, AuthorAdmin)

from django.contrib
import admin
from myapp.models
import Author

admin.site.register(Author)

from django.contrib
import admin
from.models
import Author

@admin.register(Author)
class AuthorAdmin(admin.ModelAdmin):
   pass

from django.contrib
import admin
from.models
import Author, Editor, Reader
from myproject.admin_site
import custom_admin_site

@admin.register(Author, Reader, Editor, site = custom_admin_site)
class PersonAdmin(admin.ModelAdmin):
   pass

from django.contrib
import admin

class AuthorAdmin(admin.ModelAdmin):
   date_hierarchy = 'pub_date'

date_hierarchy = 'pub_date'

class BlueEDIJobFileAdmin(admin.ModelAdmin):
   search_fields = ('blueedijob__client__code', )
list_display = ('id', 'blueedijob__client__code', )

Traceback:
File "/home/kmt/django/trunk/django/core/handlers/base.py" in get_response
  77.                     request.path_info)
File "/home/kmt/django/trunk/django/core/urlresolvers.py" in resolve
  179.             for pattern in self.urlconf_module.urlpatterns:
File "/home/kmt/django/trunk/django/core/urlresolvers.py" in _get_urlconf_module
  198.             self._urlconf_module = __import__(self.urlconf_name, {}, {}, [''])
File "/home/kmt/software/web/xword/../xword/urls.py" in <module>
  9. admin.autodiscover()
File "/home/kmt/django/trunk/django/contrib/admin/__init__.py" in autodiscover
  40.         __import__("%s.admin" % app)
File "/home/kmt/software/web/xword/../xword/crossword/admin.py" in <module>
  61. admin.site.register(Puzzles, PuzzlesAdmin)
File "/home/kmt/django/trunk/django/contrib/admin/sites.py" in register
  76.             validate(admin_class, model)
File "/home/kmt/django/trunk/django/contrib/admin/validation.py" in validate
  38.                                 % (cls.__name__, idx, field, cls.__name__, model._meta.object_name))

Exception Type: ImproperlyConfigured at /admin/crossword/authors/
Exception Value: PuzzlesAdmin.list_display[4], 'AuthorID__Notes' is not a callable or an attribute of 'PuzzlesAdmin' or found in the model 'Puzzles'.

list_display = ('foreign_key__related_fieldname1', 'foreign_key__related_fieldname2')

def foreign_field(field_name):
   def accessor(obj):
   val = obj
for part in field_name.split('__'):
   val = getattr(val, part)
return val
accessor.__name__ = field_name
return accessor

ff = foreign_field

class MyAdmin(ModelAdmin):

   list_display = [ff('foreign_key__related_fieldname1'),
      ff('foreign_key__related_fieldname2')
   ]

class FooAdmin(RelatedFieldAdmin):
   list_display = ('address__phone', 'address__country__country_code')

from django.contrib
import admin

from org.models
import Org

class OrgAdmin(admin.ModelAdmin):
   list_display = ('name', 'label') # The error was there

admin.site.register(Org, OrgAdmin)

from django.contrib.auth.admin
import UserAdmin

class PersonInline(admin.StackedInline):
   ""
" Details a person in line. "
""
model = Person
can_delete = False
verbose_name_plural = 'person'

fields = ('username', 'email', 'first_name', 'last_name', 'age', 'city', 'state')

class UserAdmin(UserAdmin):
   inlines = [
      PersonInline
   ]

# Re - register UserAdmin
admin.site.unregister(User)
admin.site.register(User, UserAdmin)

class UserAdmin(BaseUserAdmin):
   add_form = UserCreationForm

list_display = ('username', 'email', 'is_admin')
list_filter = ('is_admin', )

fieldsets = (
   (None, {
      'fields': ('username', 'email', 'password')
   }),

   ('Permissions', {
      'fields': ('is_admin', )
   }),
)

search_fields = ('username', 'email')
ordering = ('username', 'email')

filter_horizontal = ()

admin.site.register(MyUser, UserAdmin)

# bad habit to be using the old style class definition(i.e.
   `class Foo:`)
# the `@property`
decorator wont work
if you use the old style

class Sync(object):

   def __init__(self, name, value, * dependants):
   ""
"Sync the attribute `name` on all `dependants` when `self.value` is updated"
""
self._name = name
self._value = value
self._updating = False
self._dependants = list(dependants)
self._update_dependants()

@property
def value(self):
   return self._value

@value.setter
def value(self, x):
   if x != self._value:
   self._value = x
self._update_dependants()

def _update_dependants(self):
   self._updating = True
for d in self._dependants:
   if getattr(d, self._name) != self.value:
   if isinstance(d, Sync):
   if not d._updating:
   setattr(d, self._name, self.value)
else:
   setattr(d, self._name, self.value)
self._updating = False

def add_dependant(self, other):
   self._dependants.append(other)
self._update_dependants()

def del_dependnant(self, other):
   self._dependants.remove(other)

def __repr__(self):
   return "Sync('" + self._name + "': " + repr(self.value) + ")"

def __eq__(self, other):
   if isinstance(other, Sync):
   return self.value == other.value
else:
   return self.value == other

def __ne__(self, other):
   return not self.__eq__(other)

s1 = Sync('value', 2)
s2 = Sync('value', 1)
print('setup the Sync objects:')
print('>>> ' + repr(s1) + (' == '
   if s1 == s2
   else ' != ') + repr(s2))

s1.add_dependant(s2)
s2.add_dependant(s1)
print('add sync objects as dependants of each other:')
print('>>> ' + repr(s1) + (' == '
   if s1 == s2
   else ' != ') + repr(s2))

s1.value += 1
print('check that value changes transfer from one to the other:')
print('>>> ' + repr(s1) + (' == '
   if s1 == s2
   else ' != ') + repr(s2))

<figure itemprop="image" itemscope itemtype="http://schema.org/ImageObject">


   <figure itemprop="hasPart" itemscope itemtype="http://schema.org/ImageObject">

<script>
  $("input[title]").on("keyup", function () {
       /*We had emitted ToolTip attribute on our controls in Grid. 
        Those are translated to `title` in the browser. Here we are 
        picking controls based on the values that would be set by 
        asp.net while rendering grid.*/
        var $t = $(this), 
         //pick value of title or tooptip attribute of $t control
         i = $t.attr("title") || $t.attr("tooltip");

        //we get value of $t and initialize a number from it as it is a string
        var s = Number($t.val());

        //if we are not able get a number from textbox value, return
        if (isNaN(s)) return;

        //we are looking for a span which has title attribute set to value
        //we picked from textbox above also having class lbl-price 
        //and getting its text
        var p = $("span[title='" + i + "'].lbl-price").text();

        //then we get next span with same title value but class lbl-total
        // and set its text to calculated value.
        $("span[title='" + i + "'].lbl-total").text(s * +p);
  });
</script>

#we will use venv module to install Django

#navigate to your working directory and run the below command

python - m venv "vertual_environment_name"

#now activate the virtual environment

   /
   venv / scripts / activate.bat

# now Install Django

pip install django == 3.0 .8

#your virtual env should be activated

django - admin startproject "project_name"

#navigate to your project folder

python manage.py startapp "app_name"

python manage.py startapp users

#add users app to installed_apps in your settings.py file

from django.db
import models
from django.utils
import timezone
from django.utils.translation
import gettext_lazy as _
from django.contrib.auth.models
import AbstractBaseUser, PermissionsMixin, BaseUserManager

# 1. creating Custome Manager
for User Model
class CustomAccountManager(BaseUserManager):
   def create_user(self, email, user_name, first_name, password, ** other_fields):
   if not email:
   raise ValueError(_('You must provide an email address'))
# convert all in lowercase
email = self.normalize_email(email)
user = self.model(email = email, user_name = user_name,
   first_name = first_name, ** other_fields)
user.set_password(password)
user.save()
return user

def create_superuser(self, email, user_name, first_name, password, ** other_fields):
   other_fields.setdefault('is_staff', True)
other_fields.setdefault('is_superuser', True)
other_fields.setdefault('is_active', True)

if other_fields.get('is_staff') is not True:
   raise ValueError('Superuser must be assigned to is_staff=True.')
if other_fields.get('is_superuser') is not True:
   raise ValueError(
      'Superuser must be assigned to is_superuser=True.')
return self.create_user(email, user_name, first_name, password, ** other_fields)

# 2. Creating Custom User Model
class NewUser(AbstractBaseUser, PermissionsMixin):
   email = models.EmailField(_('email address'), unique = True)
user_name = models.CharField(max_length = 150, unique = True)
first_name = models.CharField(max_length = 150)
start_date = models.DateTimeField(
   default = timezone.now)
about = models.TextField(_('about'), max_length = 500, blank = True)
is_staff = models.BooleanField(
   default = False)
is_active = models.BooleanField(
   default = True)

objects = CustomAccountManager()

USERNAME_FIELD = 'email'

# required
for superuser
REQUIRED_FIELDS = ['user_name', 'first_name']

def __str__(self):
   return self.user_name

# you must have added the users app into the installed_apps
# add this attribute

AUTH_USER_MODEL = 'users.NewUser'

# it will tell Django to use this as a User Authentication model.

from django.contrib
import admin
from.models
import NewUser
from django.contrib.auth.admin
import UserAdmin
from django.forms
import Textarea

class UserAdminConfig(UserAdmin):
   model = NewUser
search_fields = ('email', 'user_name', 'first_name', )
list_filter = ('email', 'user_name', 'first_name',
   'is_active', 'is_staff')
ordering = ('-start_date', )
list_display = ('email', 'user_name', 'first_name',
   'is_active', 'is_staff')
fieldsets = (
   (None, {
      'fields': ('email', 'user_name', 'first_name')
   }), ('Permissions', {
      'fields': ('is_staff', 'is_active')
   }),
   ('Personal', {
      'fields': ('about', )
   }),
)
formfield_overrides = {
   NewUser.about: {
      'widget': Textarea(attrs = {
         'rows': 10,
         'cols': 40
      })
   },
}
add_fieldsets = (
   (None, {
      'classes': ('wide', ),
      'fields': ('email', 'user_name', 'first_name', 'password1', 'password2', 'is_active', 'is_staff')
   }),
)

admin.site.register(NewUser, UserAdminConfig)