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[Python-ideas] get() method for list and tuples
Nick Timkovichprometheus235 at gmail.com
Tue Feb 28 16:02:51 EST 2017
I wouldn't see myself using it for an arbitrary value in the middle of thelist, but perhaps for the 0th or -1st (first/last) element of a list thatmight be empty. Maybe also second-to-first/last if I'm initializing somecomparison between sequential items?Some of the examples don't work with negative indexes, boo.On Tue, Feb 28, 2017 at 12:52 PM, David Mertz <mertz at gnosis.cx> wrote:> On Tue, Feb 28, 2017 at 10:10 AM, Sven R. Kunze <srkunze at mail.de> wrote:>>> Yes, and easily written as above. What significant advantage would it>> have to spell the above as:>>>> x = alist.get(pos, default_val)>>>> It's a couple characters shorter in the proposed version. I guess I'll>> concede that needing the odd indexing at the end to get the scalar is>> slightly ugly.>>>> 1. advantage: it looks like dict access -> allows duck typing (oh how>> often I'd missed that)>> 2. advantage: no try except>> 3. advantage: no weird workaround with slices and additional item access>>>> How often would you duck-type "access either an integer position or a> named key in a collection?">> I'm all for duck typing, but it feels like those are a pretty different> pattern. For example, I know that if a list has something at index 10 it> also has something at index 9. I absolutely *do not* know that if a dict> has something at key 'g' it also has something at key 'f'.>>> --> Keeping medicines from the bloodstreams of the sick; food> from the bellies of the hungry; books from the hands of the> uneducated; technology from the underdeveloped; and putting> advocates of freedom in prisons. Intellectual property is> to the 21st century what the slave trade was to the 16th.>> _______________________________________________> Python-ideas mailing list>Python-ideas at python.org>https://mail.python.org/mailman/listinfo/python-ideas> Code of Conduct:http://python.org/psf/codeofconduct/>-------------- next part --------------An HTML attachment was scrubbed...URL: <http://mail.python.org/pipermail/python-ideas/attachments/20170228/a39b4dc1/attachment-0001.html>
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