[issue16001] small ints: cache string representation
STINNER Victor
report at bugs.python.org
Tue Sep 25 01:25:21 CEST 2012
STINNER Victor added the comment:
Here is a micro benchmark:
---
# run it using:
# benchmark.py script bench_int_str.py [--file=output]
# https://bitbucket.org/haypo/misc/src/tip/python/benchmark.py
def run_benchmark(bench):
bench.timeit('S(123)', setup='S=str')
bench.timeit('S(1) == S(2)', setup='S=str')
bench.timeit('S(12345)', setup='S=str')
bench.timeit('{S(x): x for x in data}', setup='data=tuple(range(100)); S=str')
bench.timeit('"x=%s" % x', setup='x=123')
bench.timeit('"x=%s" % x', setup='x=12345')
---
Output:
-------------------------------------------------------+-------------+---------------
Tests | unpatched | patched
-------------------------------------------------------+-------------+---------------
S=str; S(123) | 158 ns (*) | 112 ns (-29%)
S=str; S(1) == S(2) | 329 ns (*) | 248 ns (-25%)
S=str; S(12345) | 161 ns (*) | 161 ns
data=tuple(range(100)); S=str; {S(x): x for x in data} | 23 us (*) | 16.5 us (-28%)
x=123; "x=%s" % x | 145 ns (*) | 133 ns (-8%)
x=12345; "x=%s" % x | 149 ns (*) | 145 ns
-------------------------------------------------------+-------------+---------------
Total | 23.9 us (*) | 17.3 us (-27%)
-------------------------------------------------------+-------------+---------------
I expected more important speedup.
----------
Added file: http://bugs.python.org/file27285/bench_int_str.py
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<http://bugs.python.org/issue16001>
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