On 6/11/15 2:45 PM, John Dennis wrote: > On 06/11/2015 01:46 PM, Mike Bayer wrote: >> I am firmly in the "let's use items()" camp. A 100 ms difference for >> a totally not-real-world case of a dictionary 1M items in size is no >> kind of rationale for the Openstack project - if someone has a >> dictionary that's 1M objects in size, or even 100K, that's a bug in >> and of itself. >> >> the real benchmarks we should be using, if we are to even bother at >> all (which we shouldn't), is to observe if items() vs. iteritems() >> has *any* difference that is at all measurable in terms of the >> overall execution of real-world openstack use cases. These >> nano-differences in speed are immediately dwarfed by all those >> operations surrounding them long before we even get to the level of >> RPC overhead. > > Lessons learned in the trenches: > > * The best code is the simplest [1] and easiest to read. > > * Code is write-once, read-many; clarity is a vital part of the read-many. >
+1 > * Do not optimize until functionality is complete. > +1 > * Optimize only after profiling real world use cases. > +2! > * Prior assumptions about what needs optimization are almost always > proven wrong by a profiler. > +2! > * I/O latency vastly overwhelms most code optimization making obtuse > optimization pointless and detrimental to long term robustness. > Couldn't agree more > * The amount of optimization needed is usually minimal, restricted to > just a few code locations and 80% of the speed increases occur in just > the first few tweaks after analyzing profile data. > > [1] Compilers can optimize simple code best, simple code is easy to > write and easier to read while at the same time giving the tool chain > the best chance of turning your simple code into efficient code. (Not > sure how much this applies to Python, but it's certainly true of other > compiled languages.) > > John > > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Thanks, Nikhil __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
