[Python-Dev] Maintenance burden of str.swapcase

["Martin v. Löwis"]

>> Perhaps I missed something early on, but why are we proposing
>> removing a function which (presumably) is stable and tested and
>> works and is not broken? What maintenance is needed here?
> 
> 
> The maintenance burden is on other implementations.

It's not a maintenance burden (at least not in the sense in which
I understand the word "maintenance" - as an ongoing effort). When
they implement it once, the implementation can likely stay forever,
unmodified.

> Even if there is
> no maintenance burden for CPython having useless methods simply
> because  it is less effort to leave them in place creates work for
> new implementations wanting to be fully compatible.

That's true.

However, that alone is not enough reason to remove the feature, IMO.
The effort that is saved is not only on the developers of CPython,
but also on users of the feature. My claim is that for any little-used
feature, removing it costs more time world-wide than re-implementing
it in 10 alternative Python implementations (with the number 10 drawn
out of blue air), because of the cost of changing the applications that
actually do use the feature.

With the switch to Python 3, there would have been a chance to remove
little-used features. IMO, the next such chance is with Python 4.
It could be useful to start collecting little-used features that might
be removed with Python 4 - which I don't expect until 2020.

Regards,
Martin