[Python-Dev] Decision of having a deprecation period or not for changing csv.DictReader returning type. (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Sun Dec 17 13:57:39 EST 2017

On Mon, 18 Dec 2017 03:24:05 +0900 INADA Naoki <songofacandy at gmail.com> wrote:

On Mon, Dec 18, 2017 at 12:46 AM, Guido van Rossum <guido at python.org> wrote: > My gut suggests me not to do this (neither here nor in other similar cases). > I doubt there's much of a performance benefit anyway.

OrderedDict uses 2x memory than dict. So it affects memory usage of applications loading large CSV with DictReader. While I think application should use tuple when memory consumption is matter, there is significant benefit.

Or they should use a dict-of-lists instead of a list-of-dicts. Or they should simply switch to Pandas.

Simply put, I doubt using DictReader is a sensible decision if you're writing performance-sensitive code.

Regards

Antoine.

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