Generating combinations with repetitions

[Remco Gerlich]

Tomaz Ficko wrote in comp.lang.python:
> Can someone post code for generating all combinations of k elements out of n
> elements with repetitions.
> 
> Example:
> elements = 1,2,3,4  and k=3
> 
> 111, 112, 113, 114,
> 222, 221, 223, 224,
> 333, 331, 332, 334,
> 444, 441, 442, 443,
> 123, 124, 134, 234

def combs(elements, k):
    length = len(elements)
    # Compute the numer of combinations
    n = long(length) ** k
	
	result = []
    for combination in xrange(n):
       onecomb = []
       for digit in range(k):
          onecomb.append(str(elements[combination % length])
          combination = combination / length
       result.append(onecomb)
    return result

Basically, it lists the numbers 0 to length**k, written in a base that uses
'elements' as its digits.

-- 
Remco Gerlich,  scarblac at pino.selwerd.nl
"This gubblick contains many nonsklarkish English flutzpahs, but the
 overall pluggandisp can be glorked from context"  (David Moser)