Jakub Hegenbart wrote: > Hi, > > I'm studying the descriptor protocol and its usage from the following > document: > > http://users.rcn.com/python/download/Descriptor.htm > > There is some sample code: > > http://users.rcn.com/python/download/Descriptor.htm#descriptor-example > > that behaves in a different way on my machine than the example suggests: > > In [2]: a=MyClass() > > In [3]: a.x > Retrieving var "x" > Retrieving var "x" > Out[3]: 1 > > On the other hand, in the 'plain' Python shell, it's invoked only once as > expected: > >>>> a=desc.MyClass() >>>> a.x > Retrieving var "x" > 10 >>>> > > Should I take as granted that IPython might in some cases access an > attribute > of an object more than once even in face of side effects, or is this a > bug?
I'm not sure, but you could try and set up a counter that counts the number of accesses. But to be honest: I don't think it's a bug - this is one hell of an essential part of python, not working here would cause all kinds of troubles. Instead, I presume the printing/shell-part of IPython is responsible. Diez -- http://mail.python.org/mailman/listinfo/python-list
