def base_msg_type(type_):
 if (type_ is None):
  return None
 if ('[' in type_):
  return type_[:type_.find('[')]
 return type_

def base_msg_type ( type_ ) : if ( type_ is None ) : return None if ( '[' in type_ ) : return type_ [ : type_ . find ( '[' ) ] return type_
compute the base data type .