все подмножества 2

s = '5678'
a = []
n = len(s)
for value_mask in range(2**n):
    mask = bin(value_mask)[2:]
    if len(mask) < n:
        mask = (n-len(mask))*'0' + mask
    subset = []
    for i in range(n):
        if mask[i] == '1':
            subset.append(s[i])

    a.append(subset)

for x in a:
    print(*x)
print(a)
'''
z = '00101'
i = z.index('1')
print(z[i:])