[Tutor] Print a list in columnar format

[Douglas N. Shawhan]

Using a '-' in front of a string will left-justify the string in the output.
You can change the offset by placing an integer between the '%' and the 
's' in a string substitution.

Like so:

import random
for each in range(20):
    print '%10s %-10s'%(random.randint(1,10000), random.randint(1,100000))

      2305 59532    
      5211 49815    
      4685 72079    
      3752 64024    
      3528 21127    
      6577 56976    
      7072 29711    
      2106 23914    
       273 9873     
      5553 20319    
      9932 8607     
      9312 21973    
      6650 77566    
      2807 20809    
      8398 6245     
      8005 99265    
      6608 76452    
      2207 92504    
       236 31435    
      1175 24644    

(if you are not viewing this message in a monospaced font it won't be as 
impressive! Looks nice in the interpreter, though.

It works for more than two columns:
 >>> for each in range(20):
...     print '%10s %-10s %20s' %(random.randint(1,10000), 
random.randint(1,100000), random.randint(1000, 100000))
...
      8842 93134                     43106
      1313 27495                     66077
      9827 52848                     15149
       992 47592                     54314
      6661 71357                     38458
      1903 75534                     87374
      5183 95922                      7436
      4553 39353                     61334
      3067 84029                     48230
      2574 21826                     52559
      4239 6424                      11370
      2271 34964                      4177
      9770 90979                     39463
      6787 50783                     98180
      1679 29670                     65847
      6515 29142                     78164
      7406 76963                     57462
      6717 79017                     66864
      5467 17790                      5714
      4977 15100                     45395

Play with it for a while! It makes sense!