#------------------------------------------------------------------------------- # File: more_function_decorators.py # # Description: A more complex example of how to write your own decorators in # Python. # Uses Python v3.0. # # (C) 2009 by Ariel Ortiz, Tecnologico de Monterrey, Campus Estado de Mexico. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #------------------------------------------------------------------------------- class swallow_ver1: class helper: def __init__(self, outer, fun): self.outer = outer self.fun = fun def __call__(self, *args, **kwargs): try: return self.fun(*args, **kwargs) except self.outer.exceptions: return self.outer.default def __init__(self, default=None, exceptions=BaseException): self.default = default self.exceptions = exceptions def __call__(self, fun): return swallow.helper(self, fun) #------------------------------------------------------------------------------- def swallow_ver2(default=None, exceptions=BaseException): def helper1(fun): def helper2(*args, **kwargs): try: return fun(*args, **kwargs) except exceptions: return default return helper2 return helper1 #------------------------------------------------------------------------------- # Specify here what version of the swallow decorator you want to use: # swallow = swallow_ver1 swallow = swallow_ver2 @swallow(exceptions=TypeError, default='Huh?') @swallow(exceptions=ZeroDivisionError, default=0) def divide(dividend=0, divisor=1): return dividend / divisor