'int'对象在python中不可调用

Question

我得到了这个，我期望它在打印x.withdraw（）时能打印410。

Kyle 12345 500
Traceback (most recent call last):
    File "bank.py", line 21, in <module>
        print x.withdraw()
TypeError: 'int' object is not callable

这是我的代码：

class Bank:
    def __init__(self, name, id, balance, withdraw):
        self.name = name
        self.id = id
        self.balance = balance
        self.withdraw = withdraw
    def print_info(self):
        return "%s %d %d" % (self.name, self.id, self.balance)
    def withdraw(self):
        if self.withdraw > self.balance:
            return "ERROR: Not enough funds for this transfer"
        elif self.withdraw < self.balance and self.withdraw >= 0:
            self.balance = self.balace - self.withdraw
            return self.balance
        else:
            return "Not a legitimate amount of funds"

x = Bank("Kyle", 12345, 500, 90)
print x.print_info()
print x.withdraw()

我是否需要在类本身中修复某些问题，或者我的方法调用有问题？

Answer 1

您在实例上设置具有相同名称的属性：

self.withdraw = withdraw

您正在尝试调用的是该属性，而不是方法。Python不会区分方法和属性，它们也不位于单独的命名空间中。

为属性使用其他名称；withdrawn（退出的过去时）作为更好的属性名称浮现在脑海：

class Bank:
    def __init__(self, name, id, balance, withdrawn):
        self.name = name
        self.id = id
        self.balance = balance
        self.withdrawn = withdrawn
    def print_info(self):
        return "%s %d %d" % (self.name, self.id, self.balance)
    def withdraw(self):
        if self.withdrawn > self.balance:
            return "ERROR: Not enough funds for this transfer"
        elif self.withdrawn < self.balance and self.withdrawn >= 0:
            self.balance = self.balance - self.withdrawn
            return self.balance
        else:
            return "Not a legitimate amount of funds"

（我也纠正了一个错字；您曾balace在打算使用的位置使用过balance）。