old_contents: from django import forms
  from models import Post
  
  class PostForm(forms.ModelForm):
      class Meta:
          model = Post
          fields = ('title', 'text',)
          
  
new_contents: from django import forms
  from .models import Post
  
  class PostForm(forms.ModelForm):
      class Meta:
          model = Post
          fields = ('title', 'text',)
  
subject: fix import