Making all possible combinations of a list

I need to be able to make a list that contains all possible combinations of an inputted list.
For example the list [1,2,3] should return [1 [1,2] [1,3] 2 [2,3] 3 [1,2,3]]
The list doesn’t have to be in any particular order. On this site I’ve found lots of functions using the itertools but those are returning objects when I need just a list.