def archiver(typename):
 archiver = _ARCHIVER_BY_TYPE.get(typename)
 if (not archiver):
  raise ValueError(u'No archiver registered for {!r}'.format(typename))
 return archiver

def archiver ( typename ) : archiver = _ARCHIVER_BY_TYPE . get ( typename ) if ( not archiver ) : raise ValueError ( u'No archiver registered for {!r}' . format ( typename ) ) return archiver
returns archivers in common configurations .