[Tutor] Need to be taught a trick or two about printing in neat columns

[Dick Moores]

At 03:31 AM 11/2/2006, you wrote:
>At 03:13 AM 11/2/2006, Kent Johnson wrote:
> >Luke Paireepinart wrote:
> > > Instead of helping you with your specific problem, I'll give you this
> > > information and see what you can make of it.
> > >
> > >  >>> print 'a'.ljust(20)+'b'.ljust(20)
> > > a                   b
> > >  >>> print 'carrah'.ljust(20)+'foobar'.ljust(20)
> > > carrah              foobar
> >
> >Another way to do this is with string formatting, I think it is a more
> >readable and flexible solution:
> >
> >In [1]: print '%-20s %-20s' % ('a', 'b')
> >a                    b
> >
> >In [2]: print '%-20s %-20s' % ('carrah', 'foobar')
> >carrah               foobar
> >
> >See this page for details:
> >http://docs.python.org/lib/typesseq-strings.html
>
>Thanks, Kent. I agree. So now that function has become
>
>def printListOfAllUnitsAndAbbreviations():
>          """
>          Prints a 3-column list of all units and their abbreviations,
>but not their categories.
>          """
>          lstAll = allUnitsAndTheirAbbreviationsAndCategories()
>          for i in range(0, len(lstAll)-1 ,3):
>                  print '%-27s %-27s %-27s' % (lstAll[i][2:],
>lstAll[i+1][2:], lstAll[i+2][2:])
>          print

Oops! Got overconfident. Didn't check to see if it actually printed 
the whole list. It didn't. Left off "rad: radian", because there are 
46 items in the list (46%3 is 1, not 0). So now the only way I could 
see to print all 46 was to add 2 empty dummies to make 48, which is 
divisible by 3, and also modify the range in the second function. Is 
there a better way, which is also a general solution that will work 
when I subtract or add to the list? See the two  modified functions below.

Dick


def allUnitsAndTheirAbbreviationsAndCategories():
         """
         A list of all units, their abbreviations and categories.
         """
         abbs = [
         'l mi: mile',
         'l km: kilometer',
         'l m: meter',
         'l yd: yard',
         'l ft: foot',
         'l in: inch',
         'l cm: centimeter',
         'l mm: millimeter',
         'l fur: furlong',
         'l lea: league',
         'l nm: nautical mile',
         'a ha: hectare',
         'a ac: acre',
         'a mi2: square mile',
         'a km2: square kilometer',
         'a m2: square meter',
         'a yd2: square yard',
         'a ft2: square foot',
         'a in2: square inch',
         'a cm2: square centimeter',
         'w kg: kilogram',
         'w lb: pound',
         'w gm: gram',
         'w oz: ounce',
         'v qt: quart',
         'v oz: ounce',
         'v l: liter',
         'v ml: milliliter',
         'v gal: gallon',
         'v tbsp: tablespoon',
         'v tsp: teaspoon',
         'v impgal: Imperial Gallon',
         'v yd3: cubic yard',
         'v m3: cubic meter',
         'v ft3: cubic foot',
         'v mi3: cubic mile',
         'v km3: cubic kilometer',
         't F: Fahrenheit',
         't C: Celsius',
         't K: Kelvin',
         's mph: miles per hour',
         's knots: knots',
         's mps: miles per second',
         's fps: feet per second',
         'd deg: degree',
         'd rad: radian',
         '           ',
         '           '
         ]
         return abbs

def printListOfAllUnitsAndAbbreviations():
         """
         Prints a 3-column list of all units and their abbreviations, 
but not their categories.
         """
         lstAll = allUnitsAndTheirAbbreviationsAndCategories()
         for i in range(0, len(lstAll), 3):
                 print '%-27s %-27s %-27s' % (lstAll[i][2:], 
lstAll[i+1][2:], lstAll[i+2][2:])
         print