old_contents: import re
  
  from bs4 import BeautifulSoup
  from django import forms
  from django.utils.translation import ugettext_lazy as _
  
  from .models import IframePlugin
  
  
  class EmbedURLField(forms.URLField):
      widget = forms.Textarea
  
      def clean(self, value):
          if re.search(r'<iframe', value, re.IGNORECASE):
              soup = BeautifulSoup(value)
              src = soup.iframe.get('src')
              if not src:
                  raise forms.ValidationError(
                      _('The `iframe` HTML snippet was passed, but there is no '
                        '`src` arrtibute was found'),
                      code='invalid')
              value = src
          return super(EmbedURLField, self).clean(value)
  
  
  class IframeForm(forms.ModelForm):
      src = EmbedURLField(
          label=_('Embed'),
          help_text=_('Embed url or whole html embed code'))
  
      class Meta:
          model = IframePlugin
          # Set fields list explicitly, because of Django 1.8 requiremets.
          # We cannot use fields = '__all__' because of Django 1.5.
          exclude = ('id',)
  
new_contents: import re
  
  from bs4 import BeautifulSoup
  from django import forms
  from django.utils.translation import ugettext_lazy as _
  
  from .models import IframePlugin
  
  
  class EmbedURLField(forms.URLField):
      widget = forms.Textarea
  
      def clean(self, value):
          if re.search(r'<iframe', value, re.IGNORECASE):
              soup = BeautifulSoup(value)
              src = soup.iframe.get('src')
              if not src:
                  raise forms.ValidationError(
                      _('The `iframe` HTML snippet was passed, but there is no '
                        '`src` arrtibute was found'),
                      code='invalid')
              value = src
          return super(EmbedURLField, self).clean(value)
  
  
  class IframeForm(forms.ModelForm):
      src = EmbedURLField(
          label=_('Embed'),
          help_text=_('Embed url or whole html embed code'))
  
      class Meta:
          model = IframePlugin
          # Set fields list explicitly, because of Django 1.8 requirements.
          # We cannot use fields = '__all__' because of Django 1.5.
          exclude = ('id',)
  
subject: fix comment typo