Message180449
I don't believe it either. I find join consistently faster than format:
python2.7 -m timeit -s 'x = [b"x"*1000']*10 'b"".join(x)'
1000000 loops, best of 3: 0.686 usec per loop
python2.7 -m timeit -s 'x = b"x"*1000'
'(b"{}{}{}{}{}{}{}{}{}{}").format(x, x, x, x, x, x, x, x, x, x)'
100000 loops, best of 3: 2.37 usec per loop
Try longer strings, same results (though less pronounced):
python2.7 -m timeit -s 'x = [b"x"*10000']*10 'b"".join(x)'
100000 loops, best of 3: 3.54 usec per loop
python2.7 -m timeit -s 'x = b"x"*10000'
'(b"{}{}{}{}{}{}{}{}{}{}").format(x, x, x, x, x, x, x, x, x, x)'
100000 loops, best of 3: 7.35 usec per loop
I'm guessing the advantage of format() is that it allows the
occasional formatting of a float or int.
And % is not significantly faster:
python2.7 -m timeit -s 'x = b"x"*1000' '(b"%s%s%s%s%s%s%s%s%s%s") %
(x, x, x, x, x, x, x, x, x, x)'
100000 loops, best of 3: 2.31 usec per loop
python2.7 -m timeit -s 'x = b"x"*10000' '(b"%s%s%s%s%s%s%s%s%s%s") %
(x, x, x, x, x, x, x, x, x, x)'
100000 loops, best of 3: 6.81 usec per loop
python2.7 -m timeit -s 'x = b"x"*100000' '(b"%s%s%s%s%s%s%s%s%s%s") %
(x, x, x, x, x, x, x, x, x, x)'
1000 loops, best of 3: 565 usec per loop |
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Date |
User |
Action |
Args |
2013-01-23 08:02:35 | gvanrossum | set | recipients:
+ gvanrossum, loewis, terry.reedy, exarkun, pitrou, vstinner, eric.smith, christian.heimes, benjamin.peterson, glyph, ezio.melotti, arjennienhuis, uau, martin.panter, serhiy.storchaka |
2013-01-23 08:02:35 | gvanrossum | link | issue3982 messages |
2013-01-23 08:02:35 | gvanrossum | create | |
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