Question

嘿伙计我正在研究一个python程序而且我一直在从循环返回错误，这应该只是重新提示用户输入一个数字。我遇到的问题是它不断返回一个非类型，它不能用于操作我需要做的其他函数，任何帮助是值得赞赏的。谢谢。

（这是我的代码，如果格式不正确，请提前抱歉。）

def getTickets(limit):
   ticketSold=int(input("How many tickets were sold? "))
   if (ticketsValid(ticketSold,limit)):
        return ticketSold
   else:
        getTickets(limit)

#This function checks to make sure that the sold tickets are within the Limit of seats
def ticketsValid(sold,limit):

    if (sold>limit or sold<0):
        print ("ERROR: There must be tickets less than "+str(limit)+" and more than 0")
        return False
    return True
# This function calculates the price of the tickets sold in the section.
def calcIncome(ticketSold,price):
    return ticketSold*(price)

Answer 1

您没有在getTickets(limit)区块内返回else：

def getTickets(limit):
   ticketSold=int(input("How many tickets were sold? "))
   if (ticketsValid(ticketSold,limit)):
        return ticketSold
   else:
        return getTickets(limit)  # You need to use return here

Answer 2

如果没有返回任何内容，Python函数默认返回None。你有一个else子句来调用一个函数，但是没有对它执行任何操作，并且函数在那里结束，因此如果它向下控制流路径，你将从该函数返回None。

类型错误：不支持的操作数类型Int和NoneType

2 个答案: