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

[Markus Rosenstihl]

Am 02.11.2006 um 15:14 schrieb 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
>


Try somthing like this:

In [32]: a=range(100)
In [33]: for i in range(0,len(a)):
    ....:     print '%-27s'%a[i],
    ....:     if (i+1)%3 == 0: print "\n"

0                           1                           2

3                           4                           5
...
93                          94                          95

96                          97                          98

99


Note the comma after the first print statement

Regards
Markus