On Mar 8, 4:15 pm, "Terry Reedy" <[EMAIL PROTECTED]> wrote: > "egbert" <[EMAIL PROTECTED]> wrote in message > > news:[EMAIL PROTECTED] > | However the loop-else really works more like this: > | . try to do the loop; > | . if it starts but is interrupted by a break, > | . then do something else as well. > > This is NOT how loop-else works for Python. > If you want to do something special on breaks, > put the break-only code before the break. > > while loop_condition: > <loop statements> > if break_condition: > <break-only statements> > break > <more loop stuff> > > | So they are completely different beasts, and if you try to use > | or explain the one according to the rules of the other one, > | you put a serious strain on your synapses. > > I did not mean to broke your brain. > > | The explanation that the if-else and the loop-else > | follow the same pattern, runs more or less like this: > | . all conditions to run the loop to its completion were met, > | . which means that the loop-condition is not met (any more), > | . which means that we must do something else. > | For me that is orwellian logic: success is failure. > > I gave a clear and coherent explanation of how while derives from if, > and correspondingly, how while-else derives from if-else, to help those who > want to read and write Python code. Building on the pseudo-snippet above, > one can write > > while loop_condition: > <loop statements> > if break_condition: > <break-only statements> > break > <more loop stuff> > else: > <completion-only statements> > > Python allows one to have both break-only and completion-only sections > together in one compound statement and *without* having to fiddle with a > special flag variable. I am sorry if you cannot appreciate such elegance > and can only spit on it as 'orwellian'. > > If the sense of else were reversed, one would have to write the clumbsier > > complete = True # though false at this point > while loop_condition: > <loop statements> > if break_condition: > complete = False > break > <more loop stuff> > else: > <break-only statements> > if complete: > <completion-only statements> > > Terry Jan Reedy
Terry, instead of using "complete = True" and setting it to false on failure, why not set "loop_completed = False" and set it to True if the break condition is met? -- http://mail.python.org/mailman/listinfo/python-list
