Enumerate possible partitions of a set with M objects into N bins.

enum_parts.py

def insert(p, i, m, n):
    q = []
    for j in range(0, n):
        if j == i:
            s = set(p[j])
            s.add(m)
            q.append(s)
        else:
            q.append(p[j])
    return q

def parts(n, m):
    if n == 1:
        return [[set(range(0, m))]]
    if m == 1:
        return [[set()] * (n - 1) + [set([0])]]
    res = []
    for p in parts(n, m - 1):
        for i in range(0, n):
            res.append(insert(p, i, m - 1, n))
    return res

print(parts(2, 8))