add columnized output

cheat

@@ -1,14 +1,24 @@
 #!/usr/bin/env python
 import os
 import sys
+from itertools import izip_longest, islice
 
+def columnize(sequence, columns=2):
+    size, remainder = divmod(len(sequence), columns)
+    if remainder: 
+        size += 1
+    slices = [islice(sequence, pos, pos + size) 
+              for pos in xrange(0, len(sequence), size)]
+    return izip_longest(fillvalue='', *slices)
+
+def main():
   # assemble a keyphrase out of all params passed to the script
   keyphrase = ' '.join(sys.argv[1:])
   cheat_dir = os.path.expanduser('~') + '/.cheat/'
 
   # verify that the ~/.cheat directory exists
   if not os.path.isdir(cheat_dir):
-  print >> sys.stderr, 'The ~/.cheat directory does not exist.'
+    sys.stderr.write('The ~/.cheat directory does not exist.')
     exit()
 
   # list the files in the ~/.cheat directory
@@ -17,16 +27,20 @@ cheatsheets.sort()
 
   # print help if requested
   if keyphrase in ['', 'help', '--help', '-h']:
-  print "Usage: cheat [keyphrase]\n"
-  print "Available keyphrases:"
-  print "\n".join(cheatsheets)
+    print("Usage: cheat [keyphrase]\n")
+    print("Available keyphrases:")
+    for values in columnize(cheatsheets, 4):
+      print(" %s" % ' '.join(value.ljust(20) for value in values))
     exit()
 
   # print the cheatsheet if it exists
   if keyphrase in cheatsheets:
     with open (cheat_dir + keyphrase, 'r') as cheatsheet:
-    print cheatsheet.read()
+      print(cheatsheet.read())
 
   # if it does not, say so
   else:
-  print 'No cheatsheet found.'
+    print('No cheatsheet found.')
+
+if __name__ == '__main__':
+    main()