如何修复：TypeError 'tuple' 对象不支持项目分配

Question

The following fragment of code from this tutorial: http://www.raywenderlich.com/24252/beginning-game-programming-for-teens-with-python

for badguy in badguys:
        if badguy[0]<-64:
            badguys.pop(index)
        badguy[0]-=7
        index+=1
    for badguy in badguys:
        screen.blit(badguyimg, badguy)

is giving me a :

TypeError: 'tuple' object does not support item assignment

I understand that this could be becuse badguy is a tuple. This means it is immutable(you can not change its values) Ive tried the following:

t= list(badguy)
        t[0]= t[0]-7
        i+=1

I converted the tuple to a list so we can minus 7. But in the game nothing happens.

Does any one know what I could do?

Thanks.

Answer 1

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)

Answer 2

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.

Answer 3

你可以做一个 np.copy() 并与她一起工作。

badguy_copy = np.copy(badguy)