On 6/24/19 10:15 AM, johnf wrote: . > > Since I use a lot of similar loops to populate many dropdown controls I > started investigating the use of list comprehensions. But I can't > figure out how to use them in this loop and wonder if it will improve > the performance.
To amplify a tiny bit on what Peter said: comprehensions are a more concise way to express a loop-to-build-a-collection, but I don't believe were intended specifically as a performance improvement. They may be a little faster on the principle of "avoiding dots" - that is, the lookup every time through your loop from listname.append does take a little bit of time. And probably more significantly, append is a function that has to be called, and the setup stack frame/call/return sequence also takes some time. So depending on circumstances you may see insignificant or significant performance differences. But, again - Rule number one: only optimize when there is a proven speed bottleneck _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor