On Sat, Jul 31, 2010 at 3:39 AM, David Hutto <smokefl...@gmail.com> wrote: > On Sat, Jul 31, 2010 at 12:43 AM, David Hutto <smokefl...@gmail.com> wrote: >> 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. >> > > however, had it been a math exercise, I would have sucked in boiling > it down, initially. >
There is a difference between defining a function as a singular activity needed to be performed, and a function that serves as a tool, that asks for input and output, as well as serves several utilizations, e.g., it not only accepts the numerator/denominator, but spits out the gcd, the reduced, and the whole numeber reduced if the numerator is greater. but if they are even, will come with a little if num == den boolean, when I'm finished . _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
