Bruno Desthuilliers wrote: > mwojc a écrit : >> Hi! >> My class with implemented __getattr__ and __setattr__ methods cannot be >> pickled because of the Error: >> >> ====================================================================== >> ERROR: testPickle (__main__.TestDeffnet2WithBiases) >> ---------------------------------------------------------------------- >> Traceback (most recent call last): >> File "deffnet.py", line 246, in testPickle >> cPickle.dump(self.denet, file) >> TypeError: 'NoneType' object is not callable >> >> ---------------------------------------------------------------------- >> >> Is there an obvious reason i don't know, which prevents pickling with >> those methods (if i comment them out the pickling test passes)? >> >> I'm using Python 2.4.4 on Gentoo Linux. The mentioned methods goes as >> follows: >> >> def __setattr__(self, name, value): >> if name == 'weights': >> j = 0 >> for net in self.nets: >> w1 = self.wmarks[j] >> w2 = self.wmarks[j+1] >> net.weights = value[w1:w2] >> j += 1 >> else: >> self.__dict__[name] = value >> >> def __getattr__(self, name): >> if name == 'weights': >> j = 0 >> for net in self.nets: >> w1 = self.wmarks[j] >> w2 = self.wmarks[j+1] >> self._weights[w1:w2] = net.weights >> j += 1 >> return self._weights > > __getattr__ should raise an AttributeError when name != 'weight' instead > of (implicitely) returning None. pickle looks for a couple special > method in your object[1], and it looks like it doesn't bother to check > if what it found was really callable.
Yes, raising AttributeError helped. Thanks! > > FWIW, you'd be better using a property instead of __getattr__ / > __setattr__ if possible. You're probably right again, in this case it's better to use property. > And while we're at it, you dont need to > manually take care of your index in the for loop - you can use > enumerate(iterable) instead: > > for j, net in enumerate(self.nets): > w1 = self.wmarks[j] > w2 = self.wmarks[j+1] > self._weights[w1:w2] = net.weights > return self._weights > Sometimes i use manual handling of index because i'm convinced that enumeration is a bit slower than this. But i'm not really sure about it... Thanks again. Greetings, -- Marek -- http://mail.python.org/mailman/listinfo/python-list
