text: # -*- coding: utf-8 -*-
  
  
  def normalize_url_prefix(url_prefix):
      """Enforce a consistent URL representation
  
      The normalized prefix will begin and end with '/'. If there is no prefix
      the normalized form will be '/'.
  
      Examples:
          INPUT       NORMALIZED
          None            '/'
          ''              '/'
          '/'             '/'
          'example'       '/example/'
          '/example'      '/example/'
          'example/'      '/example/'
          '/example/'     '/example/'
  
      Args:
          url_prefix (str): The prefix
  
      Returns:
          str: The normalized prefix
      """
      if url_prefix in (None, '/', ''):
          return '/'
  
      new_url_prefix = ""
  
      # Make string begin with /
      if not url_prefix.startswith("/"):
          new_url_prefix += '/'
  
      new_url_prefix += url_prefix
  
      # Make string end with /
      if not url_prefix.endswith("/"):
          new_url_prefix += '/'
  
      return new_url_prefix
  