old_contents: from decimal import Decimal as D
  from decimal import InvalidOperation
  
  from babel.numbers import format_currency
  from django import template
  from django.conf import settings
  from django.utils.translation import get_language, to_locale
  
  register = template.Library()
  
  
  @register.filter(name='currency')
  def currency(value, currency=None):
      """
      Format decimal value as currency
      """
      try:
          value = D(value)
      except (TypeError, InvalidOperation):
          return u""
      # Using Babel's currency formatting
      # http://babel.pocoo.org/docs/api/numbers/#babel.numbers.format_currency
      kwargs = {
          'currency': currency if currency else settings.OSCAR_DEFAULT_CURRENCY,
          'format': getattr(settings, 'OSCAR_CURRENCY_FORMAT', None),
          'locale': to_locale(get_language() or settings.LANGUAGE_CODE),
      }
      return format_currency(value, **kwargs)
  
new_contents: from decimal import Decimal as D
  from decimal import InvalidOperation
  
  from babel.numbers import format_currency
  from django import template
  from django.conf import settings
  from django.utils.translation import get_language, to_locale
  
  register = template.Library()
  
  
  @register.filter(name='currency')
  def currency(value, currency=None):
      """
      Format decimal value as currency
      """
      try:
          value = D(value)
      except (TypeError, InvalidOperation):
          return u""
      # Using Babel's currency formatting
      # http://babel.pocoo.org/en/latest/api/numbers.html#babel.numbers.format_currency
      kwargs = {
          'currency': currency if currency else settings.OSCAR_DEFAULT_CURRENCY,
          'format': getattr(settings, 'OSCAR_CURRENCY_FORMAT', None),
          'locale': to_locale(get_language() or settings.LANGUAGE_CODE),
      }
      return format_currency(value, **kwargs)
  
subject: Update reference to babel documentation