Question

If I need to divide for example 7 into random number of elements of random size, how would I do this?

So that sometimes I would get [3,4], sometimes [2,3,1] and sometimes [2,2,1,1,0,1]?

I guess it’s quite simple, but I can’t seem to get the results. Here what I am trying to do code-wise (does not work):

def split_big_num(num):
    partition = randint(1,int(4))
    piece = randint(1,int(num))
    result = []
    for i in range(partition):
        element = num-piece
        result.append(element)
        piece = randint(0,element)
#What's next?
        if num - piece == 0:
            return result
    return result

EDIT: Each of the resulting numbers should be less than initial number and the number of zeroes should be no less than number of partitions.

Answer 1

I’d go for the next:

>>> def decomposition(i):
        while i > 0:
            n = random.randint(1, i)
            yield n
            i -= n

>>> list(decomposition(7))
[2, 4, 1]
>>> list(decomposition(7))
[2, 1, 3, 1]
>>> list(decomposition(7))
[3, 1, 3]
>>> list(decomposition(7))
[6, 1]
>>> list(decomposition(7))
[5, 1, 1]

However, I am not sure if this random distribution is perfectly uniform.