[Python-Dev] More optimisation ideas

[Serhiy Storchaka]

On 30.01.16 18:31, Steve Dower wrote:
> On 30Jan2016 0645, Serhiy Storchaka wrote:
>> $ ./python -m timeit -s "import codecs; from encodings.cp437 import
>> decoding_table" -- "codecs.charmap_build(decoding_table)"
>> 100000 loops, best of 3: 4.36 usec per loop
>>
>> Getting rid from charmap_build() would save you at most 4.4 microseconds
>> per encoding. 0.0005 seconds if you have imported *all* standard
>> encodings!
>
> Just as happy to be proven wrong. Perhaps I misinterpreted my original
> profiling and then, embarrassingly, ran with the result for a long time
> without retesting.

AFAIK the most time is spent in system calls like stat or open. 
Archiving the stdlib into the ZIP file and using zipimport can decrease 
Python startup time (perhaps there is an open issue about this).