On Wednesday, 12 April 2017 10:57:10 UTC+1, bart...@gmail.com wrote: > On Wednesday, 12 April 2017 07:48:57 UTC+1, Steven D'Aprano wrote:
> > for i in range(10): > > answer += 1 > > So... how exactly does the compiler prohibit stupid code? > And this lookup happens for every loop iteration. I've just looked at byte-code for that loop (using an on-line Python as I don't have it on this machine). I counted 7 byte-codes that need to be executed per iteration, plus five to set up the loop, one of which needs to call a function. My language does the same loop with only 4 byte-codes. Loop setup needs 2 (to store '10' into the loop counter). It also has the option of using a loop with no control variable (as it's not used here). Still four byte-codes, but the looping byte-code is a bit faster. Plus there is the option of using ++answer instead of answer += 1. Now there are only two byte-codes! (NB don't try ++ in Python.) These are straightforward language enhancements. -- bartc -- https://mail.python.org/mailman/listinfo/python-list
