On Sat, Jul 31, 2010 at 12:37 AM, David Hutto <smokefl...@gmail.com> wrote: > On Fri, Jul 30, 2010 at 11:51 PM, Steven D'Aprano <st...@pearwood.info> wrote: >> On Sat, 31 Jul 2010 01:03:27 pm David Hutto wrote: >> >>> This fixes the floating point 'bug' when numerator is greater than >>> denominator: http://python.pastebin.com/bJ5UzsBE >> >> I don't mean to be disparaging ... ah hell, who am I fooling? Yes I do. >> What is that mess? *wink* > It works except under [3], and that's fixable. And even, I know it's a > good gradumacated the eighth grade, newbie attempt.*winks* back. >> >> I can see at least four problems with that: >> >> 1. You have a function called "gcd" that doesn't calculate the gcd, but >> does something else as well. That makes it a misleading name. > > I still have the habit of wanting to use the functions like I would an > instance of the functions. > >> >> 2. The principles of code reuse and encapsulation suggest that each >> function should (as much as possible) do one thing, and do it well. You >> have a function that tries to do two or three things. You should have a >> single function to calculate the gcd, and a second function to use the >> gcd for reducing a fraction as needed, and potentially a third function >> to report the results to the user. > > Then maybe I should have done a larger class of functions instead then? > > >> >> 3. Your function has a serious bug. To see it, call gcd(5, 5) and see >> what it doesn't do. > > I'll get to it, but it seems like I had that in the original, not the > revised, maybe not, but did all other test cases for it, other than > that > > > >> >> 4. Code duplication. Your function repeats fairly major chunks of code. >> Copy-and-paste programming is one of the Deadly Sins for programmers. >> The way to get rid of that is by encapsulating code in functions (see >> point 1 above). > > I thought about putting certain print statements in a function, as > well as seperating the gcd into a from fractions import *, with a > different parameter for each if the returning if placed it into the > called function, but it seemed a little *overkill*, when it worked > well within the single function, with a few parameters placed in > through an instance with input. > >> >> >> >> -- >> Steven D'Aprano >> _______________________________________________ >> Tutor maillist - tu...@python.org >> To unsubscribe or change subscription options: >> http://mail.python.org/mailman/listinfo/tutor >> >
But, just to say, it started out as just trying to calculate the GCD with your current python skills(not import fractions, and print(gcd(3,9))for a practice exercise, and the rest is just the input, and stated output. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
