Boolean

Some boolean logic

player.buttons =      000011001000 (2**3 + 2**6 + 2**7 = 200)
PlayerButtons.DUCK =  000010000000 (2**7 = 128)
PlayerButtons.JUMP =  000001000000 (2**6 = 64)
PlayerButtons.USE =   000000001000 (2**3 = 8)
PlayerButtons.SCORE = 010000000000 (2**10 = 1024)
That means that the player is holding DUCK, JUMP and USE.

To add to that list SCORE, you should use a | operator:
player.buttons |=     010000000000

Now player.buttons equals to:
                      010011001000 (2**3 + 2**6 + 2**7 + 2**10 = 1224)

To remove DUCK from the list, you can first negate DUCK using ~ operator:
                      111101111111

Now if you apply it with &=, all bits will stay the same, except one. One bit will be nulled:
player.buttons &=     111101111111

Now player.buttons equals to:
                      010001001000