> What you are try to do is "execute a block of code based on the value of > a single statement." if/elif doesn't do that and thereby introduces the > possibility of errors.
In that case the best solution is a dictionary jump table. That is more maintainable than either and much faster too. And its also shorter to write. [Especially with lambdas :-)] > Note that the logic intended is that "on-this." So why force the > programmer to rewrite it N times and thereby introduce the possibility > of N-1 typographical errors... Thats a fair point although the dictionary solution avoids that. OTOH such switches tend to proliferate thropugh code and become a big source of maintenance headaches in their own right - multiple update syndrome across multiple files potentially. > Note that I've left out break. I'm not convinced that > fall-through is an important feature in switch and is > usually the culpit in the cases of abuse. The problem is its so hard to tell when fall though is happening intentionally or by accident because someone forgot a break sytatement. But when it comes to abuuse the fall through mechanism is one of the worst offenders in C, its just too tempting to be "clever" with it. > This is also true for the ternary operator. The desired logic is to > assign the value of a variable based on the value of some other > variable. But its not its based on the value of an *expression*. If the test could be limited to a single valiable value it might be justified but its an arbitrary expression. That makes it a conditional statement, which is most clearly represented by an if/else... Well I think so :-) > I also like Perl's unless statement but really prefer > VBs DO/WHILE/UNTIL/LOOP constuct. Nothing beats it for > clarity of expression. I won't argue on either point, Python's minimalist approach - there's only one way to do it - means a paucity of looping constructs - something I point out in my tutorial. But I can live with it for the other niceties it brings. Alan G. _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
