How to fix a : TypeError 'tuple' object does not support item assignment

Change this

badguy[0]-=7

into this

badguy = list(badguy)
badguy[0]-=7
badguy = tuple(badguy)

Alternatively, if you can leave badguy as a list, then don't even use tuples and you'll be fine with your current code (with the added change of using lists instead of tuples)

Another solution is instead of

badguy[0] -= 7

to do

badguy = (badguy[0] - 7,) + badguy[1:]

This creates a new tuple altogether with the updated value in the zeroth element.