def get_writer(extension):
 global FORMAT_WRITERS
 if (FORMAT_WRITERS is None):
  _import_writers()
 return FORMAT_WRITERS.get(extension, None)

def get_writer ( extension ) : global FORMAT_WRITERS if ( FORMAT_WRITERS is None ) : _import_writers ( ) return FORMAT_WRITERS . get ( extension , None )
returns none if no writer is found for extension .