[Python-Dev] Joys of Optimization (original) (raw)

Brett C. bac at OCF.Berkeley.EDU
Wed Mar 17 22:40:17 EST 2004

Raymond Hettinger wrote:

For those with an interest, here are some timing scorecards which track the performance of dictionary iteration:

C:\python24\python timedictiter.py 0.638557468278 keys() 0.648748721903 values() 2.97803432843 items() 1.04057057611 list(d) 1.19934712281 tuple(d) 2.23167921018 for k in d.iterkeys(): pass 2.2001936003 for v in d.itervalues(): pass 4.07347675958 for k, v in d.iteritems(): pass C:\pydev>\python23\python timedictiter.py 0.886520893746 keys() 0.861855713304 values() 3.44381233343 items() 6.86479910827 list(d) 2.48302854557 tuple(d) 2.85350994821 for k in d.iterkeys(): pass 2.8332120887 for v in d.itervalues(): pass 6.70084312509 for k, v in d.iteritems(): pass C:\pydev>\python22\python timedictiter.py 0.81167636065 keys() 0.893352218441 values() 2.99887443638 items() 6.83444576677 list(d) 2.48634656967 tuple(d) 4.54763489163 for k in d.iterkeys(): pass 4.53761544779 for v in d.itervalues(): pass 7.77635645921 for k, v in d.iteritems(): pass

Interesting how items() slowed down between 2.2 and 2.3 but is now a sliver faster than 2.2 was.

All very cool, Raymond. Cleaner code and faster to boot! Thanks for doing this.

-Brett

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