How do bitwise operations work in Python?

Assuming that values are 32 bits, 10 is

00000000000000000000000000001010

and if you invert all those bits, you get

11111111111111111111111111110101

or -11. Because it's a 2's complement system!

11011 is not -11. You have a misunderstanding of the encoding scheme for negative numbers.

In two's complement, -11 is 10101 which is the correct bit inversion.

To negate a two's complement number, you invert all bits and add one:

01011 eleven
10100 invert
10101 add one gives negative eleven