old_contents: from django.contrib.auth.models import User
  from django import forms
  
  from apps.categories.models import *
  from apps.books.models import *
  
  class LoginForm(forms.ModelForm):
      """docstring for LoginForm"""
      class Meta:
          model = User
          fields = ['username', 'password']
  
  class CategoryForm(forms.ModelForm):
          """docstring for CategoryForm"""
          class Meta:
              model = Category
              fields = '__all__'
  
  class BookForm(forms.ModelForm):
      """docstring for BookForm"""
      class Meta:
          model = Book
          fields = ('title', 'description', 'slug', 'categories',
                      'pages', 'author', 'publish_date', 'cover', 'price')
  
          widgets = {
              'categories': forms.widgets.SelectMultiple(
                  attrs={'class': 'form-control select2',
                          'style': 'width: 100%;',
                          'multiple': "multiple"}),
          }
  
new_contents: from django.contrib.auth.models import User
  from django import forms
  
  from apps.categories.models import *
  from apps.books.models import *
  
  
  class CategoryForm(forms.ModelForm):
          """docstring for CategoryForm"""
          class Meta:
              model = Category
              fields = '__all__'
  
  class BookForm(forms.ModelForm):
      """docstring for BookForm"""
      class Meta:
          model = Book
          fields = ('title', 'description', 'slug', 'categories',
                      'pages', 'author', 'publish_date', 'cover', 'price')
  
          widgets = {
              'categories': forms.widgets.SelectMultiple(
                  attrs={'class': 'form-control select2',
                          'style': 'width: 100%;',
                          'multiple': "multiple"}),
          }
  
subject: Remove unused FormLogin in admin app