All permutations from 2 lists

[Larry Martell]

If I have 2 lists, e.g.:

os = ["Linux","Windows"]
region = ["us-east-1", "us-east-2"]

How can I get a list of tuples with all possible permutations?

So for this example I'd want:

[("Linux", "us-east-1"), ("Linux", "us-east-2"), ("Windows",
"us-east-1"), "Windows", "us-east-2')]

The lists can be different lengths or can be 0 length. Tried a few
different things with itertools but have not got just what I need.

TIA!