Question

我正在编写一个简单的程序，我无法摆脱这个循环。我想要做的是如果提款金额大于您的余额，请转到while循环。 while循环应该获得一个新输入并检查新输入是否大于余额，如果是重复，如果不是则转到else，这是我打印余额的位置

class Account(object):
balance = 0
accountNumber = 0

def __init__(self, f, l, ssn, b):
    self.firstName = f
    self.lastName = l
    self.socialSecurity = ssn
    self.balance = b
    self.accountNumber = randint(0, 10000)

def __str__(self):
    return self.firstName + " " + self.lastName + \
           "'s balance is $" + str(self.balance) + \
           ". Your account Number is " + str(self.accountNumber)

def deposit(self, amount):
    depositAmount = amount
    balance = self.balance + depositAmount

    print(str(depositAmount) + " has been deposited into account "
                               "#" + str(
        self.accountNumber) + " Your balance is "
                              "now " + str(balance))
    return self.balance

def withdraw(self, amount):
    withdrawAmount = amount
    balance = self.balance - withdrawAmount
    if float(withdrawAmount) > float(balance):
        while float(withdrawAmount) > float(balance):
            print("Insufficient Funds, Enter new amount")
            withdrawAmount = raw_input(">")
    else:
       print(str(withdrawAmount) + " has been taken out of account "
                                "#" + str(
        self.accountNumber) + " Your balance is "
                              "now " + str(balance))



testOne = Account("John", "Smith", "1111", 1000)
print(testOne)
print(testOne.accountNumber)
testOne.deposit(200)
testOne.withdraw(5000)

我的问题是，无论我说什么都输入新数量

，我陷入了while循环

Answer 1

raw_input()返回一个字符串。您需要将其转换为float或int，例如：

withdrawAmount = float(raw_input(">"))

Answer 2

Kirk是对的。

raw_input()生成字符串，而不是数值。我怀疑balance也是使用raw_input()创建的，是这样吗？如果是这样，您将字符串与字符串进行比较，而您认为比较数字。这就是你陷入这个循环的原因。确保您具有预期类型的比较变量。

试试这个：

if float(withdrawAmount) > float(balance):
        while float(withdrawAmount) > float(balance):
            print("Insufficient Funds, Enter new amount")
            withdrawAmount = raw_input(">")
else:
    print

如果这样做，我的假设可能是正确的。

但我建议在此片段之前检查您的代码，以确保balance实际上是int或float，并将withdrawAmount设置为float输入时输入（或int）（如Kirk建议的那样）;通过这种方式，您将比较数字并且一切正常。

修改

好的，我发现您的代码存在问题。您实际上从之前的余额中减去withdrawAmount 进行比较。试试这个：

def withdraw(self, amount): withdrawAmount = amount balance = self.balance while withdrawAmount > balance: print("Insufficient Funds, Enter new amount") withdrawAmount = int(raw_input(">")) balance = balance - withdrawAmount print(...)

Answer 3

试试这个：

if withdrawAmount > balance:
    while withdrawAmount > balance:
        print "Insufficient Funds, Enter new amount"
        withdrawAmount = int(raw_input())

这给了我（余额= 50）：

...
Try again
60
Try again
30
>>>

您不需要else语句，因为代码将在退出while循环后退出该块。

Answer 4

这是一种方法：

balance = 100
withdrawAmount = float(raw_input(">"))
while withdrawAmount > balance:
    withdrawAmount = float(raw_input("Insufficient Funds, Enter new amount: "))
print "Thank You"

python while循环非退出

4 个答案: