Message394049
Since strings are immutable types, we could fold some operation on top of them. Serhiy has done some work on issue 28307 regarding folding `str % args` combination, which I think we can extend even further. One simple example that I daily encounter is that, there is this pattern
'/'.join([something, something_else, user_arg])
where people would join N number of elements together with a separator, where the N is something that we know. Just a search over some locally cloned PyPI projects (a couple thousand, showed 5000+ occurrences where this optimization applies).
The preliminary benchmarks indicate that the speedup is about %40. Though there are multiple issues that might concern others:
- type checking, f-strings cast automatically but .join() requires each element to be a string subclass. The current implementation introduces a new conversion called 'c' which actually does the type checking instead of converting the value.
- preventing a call to a runtime function, I belive that this work is not that different than issue 28307 which prevents str.__mod__ though I understand the concern
Here is the implementation if anybody wants to take a look at it: https://github.com/isidentical/cpython/commit/d7ea8f6e38578ba06d28deb4b4a8df676887ec26
I believe that the implementation can be optimized further (etc if a continuous block of elements are a string, then we can load all of them in one go!). And some cases proved that the f-strings might be faster than the join by 1.7-1.8x. |
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Date |
User |
Action |
Args |
2021-05-20 19:03:34 | BTaskaya | set | recipients:
+ BTaskaya, eric.smith, serhiy.storchaka, pablogsal |
2021-05-20 19:03:34 | BTaskaya | set | messageid: <1621537414.24.0.919441492854.issue44194@roundup.psfhosted.org> |
2021-05-20 19:03:34 | BTaskaya | link | issue44194 messages |
2021-05-20 19:03:33 | BTaskaya | create | |
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