Steven D'Aprano <st...@remove-this-cybersource.com.au> wrote: > On Sat, 10 Apr 2010 16:35:29 +0000, Duncan Booth wrote: > >> Anyway, the moral is never, ever to use old-style classes in Python >> 2.x. You will get weird and unexpected results. > > That's a bit strong. They're only weird and unexpected if you're not > expecting them and don't understand them.
Which is exactly what will happen when some subclass tries to use a property not realising that it is actually an old style class. That kind of problem can be a real pain to track down. > > Why are we worrying about the exact error message? New style or old > style, they both raise TypeError, and testing for the exact error > message is a fragile, dangerous thing to do: error strings are not > part of the Python API, and are subject to change without notice, for > any reason. For all we know, Python runtimes compiled on a Tuesday > could use different error messages from runtimes compiled on > Wednesdays. > I'm intrigued by the exact error message because I'd like to know the answer to one of the questions Vicente asked: what object is being passed to 'm' on the system which complains "m() takes no arguments (1 given)" I'm sure it must just be an insignificant difference, but I hate unanswered questions. -- http://mail.python.org/mailman/listinfo/python-list
