How to pop the interpreter's stack?

[Carl Banks]

On Dec 24, 1:24 am, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> On Thu, 23 Dec 2010 22:38:05 -0800, Carl Banks wrote:
> > OTOH, going the extra mile to hide useful information from a user is
> > asinine. As a user, I will decide for myself how I want to use
> > implementation-defined information, and I don't want the implementor to
> > decide this for me. It's bad enough if an implementor fails to provide
> > information out of laziness, but when they deliberately do extra work to
> > hide information, that's self-importance and arrogance.
>
> But that of course is nonsense, because as the user you don't decide
> anything of the sort.

As a user I can criticize the decision of the implementor to
needlessly filter information, and declare that it's borne out of the
author's arrogance in thinking he knows what I want when I get a
traceback.

I can also opine that Python language shouldn't make it easy for
library implementors to be arrogant like this.

> The developer responsible for writing the function
> decides what information he provides you, starting with whether you get
> an exception at all, where it comes from, the type of exception, and the
> error message (if any). Once this information has been passed on to you,
> you're free to do anything you like with it, but you never get to choose
> what information you get -- I'm not suggesting any change there. All I'm
> suggesting is that there should be a way of reducing the boilerplate
> needed for this idiom:
>
> def _validate_arg(x):
>     if x == 'bad input': return False
>     return True
>
> def f(arg):
>     if not _validate_arg(arg):
>         raise ValueError
>     process(arg)
>
> to something more natural that doesn't needlessly expose implementation
> details that are completely irrelevant to the caller.

Arrogance.  Who gave you the right to decide what is completely
irrelevant to user?  I, as the user, decide what's relevant.  If I
want implementation-dependent information, it's my business.

I don't want the language to make it easy for arrogant people, who
think they know what information I want better than I do, to hide that
information from me.


Carl Banks