[Python-ideas] Allow key='attribute_name' to various sorting functions

[Donald Stufft]

On Apr 11, 2013, at 6:52 PM, Ram Rachum <ram.rachum at gmail.com> wrote:

> On Friday, April 12, 2013 1:35:20 AM UTC+3, Carl Meyer wrote:
> On 04/11/2013 04:24 PM, Ram Rachum wrote: 
> > I often want to sort objects by an attribute. It's cumbersome to do this: 
> > 
> >     sorted(entries, key=lambda entry: entry.datetime_created) 
> > 
> > Why not allow this instead: 
> > 
> >     sorted(entries, key='datetime_created') 
> 
>     from operator import attrgetter 
>     sorted(entries, key=attrgetter('datetime_created')) 
> 
> You can alias attrgetter to an even shorter name if you like. 
> 
> That's still cumbersome in my opinion.
>  
> 
> Explicit utility functions are better than implicit special-case 
> behaviors. Why should a string be special-cased to attribute lookup 
> rather than, say, __getitem__ lookup? 
> 
> Right, these are options too. I'd guess that attribute lookup is more common, but maybe I'm wrong.
>  
> 
> Carl 
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Special cases aren't special enough to break the rules.

-----------------
Donald Stufft
PGP: 0x6E3CBCE93372DCFA // 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA

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