def select_formatter_class(formatter_name):
 try:
  return _formatter_registry[formatter_name]
 except KeyError:
  if (':' not in formatter_name):
   raise
  return load_formatter_class(formatter_name)

def select_formatter_class ( formatter_name ) : try : return _formatter_registry [ formatter_name ] except KeyError : if ( ':' not in formatter_name ) : raise return load_formatter_class ( formatter_name )
resolve the formatter class by: * using one of the registered ones * loading a user-specified formatter class .