mwojc a écrit :
Bruno Desthuilliers wrote:
>>> class Prop(object):
... @apply
... def prop():
... def fget(self): return self._prop
... def fset(self, val): self._prop = val
... return property(**locals())
... def __init__(self, val): self.prop=val
...
>>> class Hook(object):
... def __getattr__(self, name):
... if name == 'prop':
... return self._prop
... raise AttributeError("yadda")
... def __setattr__(self, name, val):
... if name == 'prop':
... self.__dict__['_prop'] = val
... else:
... # XXX : INCORRECT IMPLEMENTATION, DONT DO THIS !
... self.__dict__[name] = val
... # correct implementation:
... # super(Hook, self).__setattr__(name, value)
... def __init__(self, val): self.prop=val
Hi!
Finally i ended up with all the suggestions you gave me. The speed is
important to me besause i get/set my attribute a lot... The only doubts i
have are with the @apply decorator, because 'apply' seems to be depreciated
since python 2.3...
As far as I can tell, it should stay until Python 3.0. But you don't
have to write your properties that way anyway - it's just something I
personnaly find to be a convenient shortcut, period. FWIW, the above
code is just a copy/paste from an interactive session, not an example of
"clean" Python coding.
And another thing: why writing for all
attributes 'self.__dict__[name] = val' in __setattr__ is incorrect?
Because __setattr__ is *always* called. With your above solution,
read/write properties setters won't be called.
Python 2.5.1 (r251:54863, Mar 7 2008, 03:41:45)
[GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> class Foo(object):
@apply
def bar():
def fget(self):
print "bar get"
return self._bar
def fset(self, val):
print "bar set"
self._bar = val
def __getattr__(self, name):
print "__getattr__", name
if name == 'baaz':
return self._baaz
raise AttributeError("yadda")
def __setattr__(self, name, val):
print "__setattr__", name
self.__dict__[name] = val
>>> foo = Foo('bar', 'baaz')
__setattr__ bar
__setattr__ baaz
>>> foo.baaz
'baaz'
>>> foo.bar
'bar'
>>> foo.__dict__
{'baaz': 'baaz', 'bar': 'bar'}
--
http://mail.python.org/mailman/listinfo/python-list
