[Python-Dev] namedtuple implementation grumble (original) (raw)

Eric V. Smith eric at trueblade.com
Mon Jun 9 03:21:42 CEST 2014

On 6/8/2014 7:31 PM, Steven D'Aprano wrote:

On Sun, Jun 08, 2014 at 03:13:55PM -0400, Eric V. Smith wrote:

On 6/7/2014 10:46 AM, Nick Coghlan wrote:

On 7 June 2014 04:50, Chris Withers <chris at simplistix.co.uk> wrote:

Curious as to what lead to that implementation approach? What does it buy that couldn't have been obtained by a mixin providing the functionality?

In principle, you could get the equivalent of collections.namedtuple through dynamically constructed classes. In practice, that's actually easier said than done, so the fact the current implementation works fine for almost all purposes acts as a powerful disincentive to rewriting it. The current implementation is also really easy to understand, while writing out the dynamic type creation explicitly would likely require much deeper knowledge of the type machinery to follow. As proof that it's harder to understand, here's an example of that dynamically creating functions and types: [...] I wonder how a hybrid approach would work? Use a dynamically-created class, but then construct the new method using exec and inject it into the new class. As far as I can see, it's only new that benefits from the exec approach. Anyone tried this yet? Is it worth an experiment?

I'm not sure what the benefit would be. Other than the ast manipulations for new, the rest of the non-exec code is easy to understand.

Eric.

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