old_contents: from django import template
  register=template.Library()
  
  @register.filter
  def stringformat(value, fmt='{}'):
     '''
     format the value
     '''
     return fmt.format(value)
  
new_contents: from django import template
  register=template.Library()
  
  @register.filter
  def stringformat(value, fmt='{}'):
     '''
     format the value
     '''
     if isinstance(value, dict):
        return fmt.format(**value)
     return fmt.format(value)
  
subject: Add named format support if dict