Question

done = False
player_health = 2
def lost_game(done):
    if player_health <= 0:
        done = True
        print ('You died')
        return done
while not done:
    print 'okay'
    player_health -= 1

我无法弄清楚为什么done永远不会设置为True，从而结束了while循环。

Answer 1

它未设置为True，因为它是一个局部变量。如果要使用函数赋值影响全局变量，则必须声明：

def lost_game():
    global done
    if player_health <= 0:
        done = True

另请注意，您从未调用lost_game函数。我不确定您期望的控制流程。 看起来就像你想要一个简单的循环一样：

done = False
player_health = 2
while not done:
    if player_health <= 0:
        done = True
        print ('You died')

print 'okay'
player_health -= 1

...或者可能只是你没有调用函数并捕获返回值：

done = False
player_health = 2

def lost_game():
    done = False
    if player_health <= 0:
        done = True
        print ('You died')
        return done

while not lost_game():
    print 'okay'
    player_health -= 1

Answer 2

你永远不会打电话给lost_game()。 lost_game()返回值作为结果，因此您应该使用它而不是变量：

player_health = 2

def lost_game():
    if player_health <= 0:
        print ('You died')
        return True
    else:
        return False

while not lost_game():
    print 'okay'
    player_health -= 1

lost_game()不需要参数。

Answer 3

只需更新你的while循环：

while not done: 
    print 'okay' 
    player_health -= 1
    done = lost_game(done)

顺便说一下，你的lost_game函数调用不需要传递。

我的函数返回值不是全局的，不会结束“while”循环

3 个答案: