[Python-Dev] optimization required: .format() is much slower than %

[Antoine Pitrou]

Nick Coghlan <ncoghlan <at> gmail.com> writes:
> 
> The only optimisation idea I came up with (other than the addition of a 
> tp_format slot) is for string objects to be able to cache their 
> (lookup:subformat) pairs rather than having to parse themselves every 
> time. That has obvious memory consumption implications though.

If a string is used as a formatting template, it is bound to be used again as
such. So IMHO it sounds quite reasonable.

In order to avoid memory consumption issues there could be a centralized cache
as for regular expressions. It makes it easier to handle eviction based on
various parameters, and it saves a few bytes for string objects which are never
used as a formatting template.

Regards

Antoine.