code: def make_python_name(s, default=None, number_prefix='N',encoding="utf-8"):
      
      if s in ('', None):
          s = default
      s = str(s)
      s = re.sub("[^a-zA-Z0-9_]", "_", s)
      if not re.match('\d', s) is None:
          s = number_prefix+s
      return unicode(s, encoding)
docs: Returns a unicode string that can be used as a legal python identifier.
  
      :Arguments:
        *s*
           string
        *default*
           use *default* if *s* is ``None``
        *number_prefix*
           string to prepend if *s* starts with a number