Let’s say the number is 123.

Then the statement: 

[int(''.join(x)) for x in permutations(list(str(123)))]
will create a sorted list of all possible numbers using ‘1’,‘2’ and ‘3’. which is, [123, 132, 213, 231, 312, 321]

What it is doing

The part, permutations(list(str('123' is creating a permutated tuples’ list of splitted string ‘123’. And the int(''.join(x)) is converting each tuple to Integer.

However, of course, you need to import permutations from itertools.

so, the generalized version would be:

from itertools import permutations
[int(''.join(x)) for x in list(permutations(list(str(n))))]

Python is fun. Isn’t it?