gh-118761: Improve import time of cmd module - #130056
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gpshead merged 4 commits intoFeb 17, 2025
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I also suggest removing import string and making the following one change: # from this:
IDENTCHARS = string.ascii_letters + string.digits + '_'
# to this:
IDENTCHARS = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'
'abcdefghijklmnopqrstuvwxyz'
'0123456789'
'_')That's all! Benchmarks for cmd module without import stringcomparing with the main branch here are the results: Total import time: 0.023s -> 0.008s = x2.88 as fast
cmd import time: 0.016s -> 0.001s = x16 as fast (or more :)
hyperfine: 23.7ms -> 9.0ms = x2.64 as fast$ hyperfine --warmup 11 "./python -c 'import cmd'"
Benchmark 1: ./python -c 'import cmd'
Time (mean ± σ): 9.0 ms ± 0.6 ms [User: 7.6 ms, System: 1.4 ms]
Range (min … max): 8.4 ms … 13.0 ms 288 runs |
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gpshead
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Go ahead and remove the import string as described. |
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gpshead
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Feb 17, 2025
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I use lazy import for inspect module (called 1 time).
And I suggest getting rid of import string. This will improve import time as much as possible (benchmarks without string module separately in second comment).
CPython configure flags:
Benchmarks:
Running: pipx install tuna && ./python -X importtime -c 'import cmd' 2> import.log && tuna import.log
Total import time: 0.023s -> 0.013s = x1.77 as fast
cmd import time: 0.016s -> 0.007s = x2.29 as fast
hyperfine: 23.7ms -> 15.0ms = x1.58 as fast
Main branch:
PR branch: