How to pop the interpreter's stack?

[Ethan Furman]

Steven D'Aprano wrote:
> Right. But I have thought of a clever trick to get the result KJ was 
> asking for, with the minimum of boilerplate code. Instead of this:
> 
> 
> def _pre_spam(args):
>     if condition(args):
>         raise SomeException("message")
>     if another_condition(args):
>         raise AnotherException("message")
>     if third_condition(args):
>         raise ThirdException("message")
> 
> def spam(args):
>     _pre_spam(args)
>     do_useful_work()
> 
> 
> you can return the exceptions instead of raising them (exceptions are 
> just objects, like everything else!), and then add one small piece of 
> boilerplate to the spam() function:
> 
> 
> def _pre_spam(args):
>     if condition(args):
>         return SomeException("message")
>     if another_condition(args):
>         return AnotherException("message")
>     if third_condition(args):
>         return ThirdException("message")
> 
> def spam(args):
>     exc = _pre_spam(args)
>     if exc: raise exc
>     do_useful_work()

-1

You failed to mention that cleverness is not a prime requisite of the 
python programmer -- in fact, it's usually frowned upon.  The big 
problem with the above code is you are back to passing errors in-band, 
pretty much completely defeating the point of have an out-of-band channel.

~Ethan~