"More About Unicode in Python 2 and 3"

[Chris Angelico]

On Mon, Jan 6, 2014 at 9:56 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> Why is a StopIteration bubbling up? (I don't have Flask, so I can't
>> verify this.) Is it as simple as "this should be raising from None",
>> or is there something else going on?
>
> Remember that "raise Spam from None" only works from Python 3.3 onwards.
> Personally, I think that releasing nested tracebacks before having a way to
> suppress the display was a strategic blunder, but it's fixed now, at least
> for those who can jump straight to 3.3 and not bother supporting 3.1 and
> 3.2.

Fair enough. If it's a problem, I'm sure Flask could do something like
(untested):

error = False
try:
    next(whatever)
except StopIteration:
    error = True
if error: raise ValueError("...")

which would work across all. But that's assuming that it really is
just a small matter of traceback ugliness. The post implies that it's
a lot worse than that.

ChrisA