[pygtk] Re: [Python-Dev] a bit confused about the new type/class stuff (original) (raw)

Skip Montanaro skip@pobox.com (Skip Montanaro)
Thu, 4 Oct 2001 08:41:48 -0500 

>> >>> l
>> [<Button object (GtkButton) at 0x8293134>, <Button object (GtkButton) at 0x8296ac4>, <Button object (GtkButton) at 0x8397fb4>]
>> >>> b = l[0]
>> >>> b in l
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in ?
>> TypeError: Button.__cmp__(x,y) requires y to be a 'Button', not a 'instance'

A brief conversation with Guido cleared up what was happening. In my class hierarchy I didn't implement cmp, but I did implement getattr, which was delegating most things to the underlying Gtk widget, so 

b.__cmp__(l)

became

b._real_widget.__cmp(l)

which then barfed.

Writing a cmp method that does the right thing cleared up the problem.

Skip