python - 如何使用 if、elif 和 else 运行多参数函数？

Question

因此，我尝试制作一个根据输入将变量加一的函数，但出现错误。

def food_ch(i, a, b, c, d):
    if a in i.lower():
        first += 1
    elif b in i.lower():
        second += + 1
    elif c in i.lower():
        third += 1
    elif d in i.lower():
        fourth += 1
    else:
        hungry += 1

 
print ("What cuisine do you like the most?: Italian, Chinese, Japanese or Mexican?")
food = input("I like ")

first = 0
second = 0
third = 0
fourth = 0
hungry = 0

food_ch(food, "italian", "chinese", "japanese", "mexican")

print (first, second, third, fourth, hungry)

Answer 1

您应该使first, second, third, fourth, hungry 变量全局。否则，您将得到 UnboundLocalError。该功能应更正如下。

def food_ch(i, a, b, c, d):
    global first, second, third, fourth, hungry    # this part should be added
    if a in i.lower():
        first += 1
    elif b in i.lower():
        second += + 1
    elif c in i.lower():
        third += 1
    elif d in i.lower():
        fourth += 1
    else:
        hungry += 1

print ("What cuisine do you like the most?: Italian, Chinese, Japanese or Mexican?")
food = input("I like ")

first = 0
second = 0
third = 0
fourth = 0
hungry = 0

food_ch(food, "italian", "chinese", "japanese", "Mexican")

print (first, second, third, fourth, hungry)