Why is __getslice__ still implemented?

Torsten Bronger bronger at physik.rwth-aachen.de
Tue Apr 10 11:15:30 CEST 2007


Hallöchen!

According to <http://docs.python.org/ref/sequence-methods.html>,
__getslice__ is deprecated.  At the moment, I derive an own class
from unicode and want to implement my own slicing.  I found that I
have to override __getslice__ since __getitem__ isn't called when I
have something like my_instance[a:b] in my code.

According to
<news:mailman.7438.1102640455.5135.python-list at python.org>, this may
have efficiency reasons, however, I agree with
news:1102645919.114898.139820 at f14g2000cwb.googlegroups.com that this
is quite confusing.  It forces people to implement a deprecated
function after all.  I think the docs should say that you still have
to override __getslice__ when subclassing from a built-in type,
unless I really don't understand the issue correctly.

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
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