我无法让函数返回全局varriab

Question

回溯（最近一次呼叫）： 文件“C:\Users\Mitch\Documents\lab3.py”，第18行，in 主（） 文件“C:\Users\Mitch\Documents\lab3.py”，第15行，main finddiscount（数量） 文件“C:\Users\Mitch\Documents\lab3.py”，第2行，在finddiscount中 如果数量>；=1且数量<；=9： NameError:未定义全局名称“quantity”

def finddiscount(discount):
    if quantity >= 1 and quantity <= 9:
        discount = "0%"
    elif quantity >= 10 and quantity <= 19:
        discount = "20%"
    elif quantity >= 20 and quantity <= 49:
        discount = "30%"
    elif quantity >= 50 and quantity <= 99:
        discount = "40%"
    elif quantity >= 100:
        discount = "50%"
    print (discount)    
def main():
    quantity = int(input("How many packages where purchased?"))
    finddiscount(quantity)
    price = float(input("How much is each item?"))
    return
main()

Answer 1

试试看

def finddiscount(quantity):   # not discount!