Recipe 576527 revision 2

immutable_types = set((int, str))

class Frozen(object):
    def __init__(self, value):
        self._value = value

    def __getattribute__(self, name):
        if name == '_value': return super(Frozen, self).__getattribute__(name)
        v = getattr(self._value, name)
        return v if v.__class__ in immutable_types else freeze(v)
  
    def __setattr__(self, name, value):
        if name == '_value': super(Frozen, self).__setattr__(name, value)
        else: raise Exception("Can't modify frozen object {0}".format(self._value))
    
def freeze(value):
  return Frozen(value)

• « Back to Recipe 576527

History

• revision 2 (15 years ago)
• previous revisions are not available