On Sun, 07 Jan 2007 04:09:13 -0800, Paul Rubin wrote: > "Felipe Almeida Lessa" <[EMAIL PROTECTED]> writes: >> What is the chance of having to inherit from two classes from >> different modules but with exactly the same name *and* the same >> instance variable name? >> >> Of course you're being very pessimistic or extremely unlucky. > > If you want to write bug-free code, pessimism is the name of the game.
I wonder whether Paul uses snow chains all year round, even in the blazing summer? After all, "if you want to drive safely, pessimism is the name of the game". In the last couple of weeks comp.lang.python has had (at least) two practical examples of the pros and cons of private attributes. The pro: there was discussion about replacing the optparse module's implementation with argparse, leaving the interface the same. This was complicated by the fact that optparse exposes its internal variables, making the job of duplicating the interface significantly harder. However this was surely a design choice, not an accident. Having private attributes won't save you if you choose not to make your attributes private. The con: there was a fellow who (for some reason) actually needed to access a class' private attributes. To the best of my knowledge, he was over 18 and, while new to Python, an experienced programmer, so I believe him when he said he had eliminated all other alternatives. (And if he were wrong, if he was incompetent -- Not My Problem. It isn't for me to take a hammer off him so he doesn't hit his thumb with it.) In his case, Python's name mangling of private attributes was an inconvenience, not a help. Compared to all the "what-ifs" and "maybes" and hypotheticals in this thread, there were two practical cases that revolved around private variables. In one, we see that they aren't a panacea: data hiding doesn't help when the data isn't hidden. In the other, we see that one developer's private attribute is just what another developer needs to solve a problem. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
