PRINT COMBINATIONS OF X FROM N

#!/usr/bin/python
# coding=utf8

# PRINT COMBINATIONS OF X FROM N
# written by Andras Horvath <han at log69.com> (2010) Public Domain

n = 6
x = 3

if (x > n): n, x = x, n

a = range (1, x+1)

while (1):

   print a

   if (a[x-1] == n):
            lim = 0
            for i in range (x, 0, -1):
               if (a[i-1] < n-(x-i)):
                  lim = i
                  break
            if (lim == 0): exit ()
            a[lim-1] += 1
            for i in range (lim+1, x+1):
               a[i-1] = a[i-2] + 1
   else:
      a[x-1] += 1