Question

我有一个班级，我期待这个：

print(rithesh.amount) = 150.

我该怎么做？

这是我的代码：

class Customer:

    total_amount = 0

    def __init__(self, name, mob, email, amount=None):
        self.name = name
        self.mob = mob
        self.eamil = email

    def add_amount(self, amount):
        self.amount = amount

rithesh = Customer("Rithesh", "8896398598", "ritheshb1@gmail.com")
rithesh.add_amount(100)
rithesh.add_amount(50)
print(rithesh.amount)

Answer 1

您可以将__init__方法中的金额变量声明为0。然后对add_amount方法进行一些小改动。

class Customer:

    total_amount = 0

    def __init__(self, name, mob, email, amount=None):
        self.name = name
        self.mob = mob
        self.eamil = email
        self.amount = 0

    def add_amount(self, amount):
        self.amount += amount

    rithesh = Customer("Rithesh", "8896398598", "ritheshb1@gmail.com")
    rithesh.add_amount(100)
    rithesh.add_amount(50)
    print(rithesh.amount)

<强>输出

Answer 2

在python中拥有属性的实际方法是使用@property decorator

例如，在您的班级中：

class Customer:

    total_amount = 0

    def __init__(self, name, mob, email, amount=None):
        self.name = name
        self.mob = mob
        self.eamil = email

    @property
    def add_amount(self):
        return  self.add_amount

    @add_amount.setter
    def add_amount(self, amount):
        self.add_amount = amount


rithesh = Customer("Rithesh", "8896398598", "ritheshb1@gmail.com")
rithesh.add_amount = 150
print(rithesh.add_amount)

Answer 3

知道怎么做。

我必须在初始化期间声明值self.amount = 0.

class Customer:

    total_amount = 0

    def __init__(self, name, mob, email, amount=None):
        self.name = name
        self.mob = mob
        self.eamil = email
        self.amount = 0

    def add_amount(self, amount):
        self.amount += amount

rithesh = Customer("Ritehsh", "8892398598", "ritheshb1@gmail.com")
rithesh.add_amount(100)
rithesh.add_amount(50)
print(rithesh.amount)

因此输出为print（rithesh.amount）= 150

Answer 4

当您拨打add_amount时，您没有将值添加到self.amount，而只是设置它。

只需更改add_amount的定义：

self.amount = amount

为：

self.amount += amount

并添加到__init__方法：

self.amount = 0

简单类属性更新

4 个答案: