AttributeError: 'ElectricCar' object has no attribute 'battery_size'

出现这种情况由于在“初始化父类的属性”（ def _ _init_ _() ）和“继承父类属性”

（ super()._ _init_ _（）），“init”两边都是两个下划线，电脑和书本分辨不出来，操作的时候太快了，可能有的地方遗漏了。对比一下程序代码：

1.有误的程序：

class Car:
    """一次模拟汽车的简单尝试"""
    def __init__(self, make, model, year): #完全看不出 init 两边各有两个下划线
        """初始化描述汽车的属性"""
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 44
    # def update_reading(self, mileage):
    #     """将里程表读书设为指定值
    #     禁止读书往回调"""
    #     if mileage >= self.odometer_reading:
    #         self.odometer_reading = mileage
    #     else:
    #         print("You can't roll back an odometer")
    #     self.odometer_reading = mileage
    def get_descriptive_name(self):
        """返回整洁的描述信息"""
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()
    # def read_odometer(self):
    #     """打印一条汽车里程的信息"""
    #     print(f"The car odometer is {self.odometer_reading} mile on it!")
class ElectricCar(Car):
    """电动车独特之处"""
    def _init_(self, make, model, year):
        """初始化父类的属性"""
        super()._init_(make, model, year)
        self.battery_size = 75
    def describe_battery(self):
        print(f"This car has a {self.battery_size}-kw battery")

my_tesla = ElectricCar('tesla', 'model s', 2019)
print(my_tesla.get_descriptive_name())
my_tesla.describe_battery()

错误处如下：

    def _init_(self, make, model, year):   #init 两边都为 一个下划线  “—”
        """初始化父类的属性"""
        super()._init_(make, model, year)  # init 两边都为 一个下划线  “—”

2.修改之后程序

class Car:
    """一次模拟汽车的简单尝试"""
    def __init__(self, make, model, year):
        """初始化描述汽车的属性"""
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 44
    # def update_reading(self, mileage):
    #     """将里程表读书设为指定值
    #     禁止读书往回调"""
    #     if mileage >= self.odometer_reading:
    #         self.odometer_reading = mileage
    #     else:
    #         print("You can't roll back an odometer")
    #     self.odometer_reading = mileage
    def get_descriptive_name(self):
        """返回整洁的描述信息"""
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()
    # def read_odometer(self):
    #     """打印一条汽车里程的信息"""
    #     print(f"The car odometer is {self.odometer_reading} mile on it!")
class ElectricCar(Car):
    """电动车独特之处"""
    def __init__(self, make, model, year):  #修改之后
        """初始化父类的属性"""
        super().__init__(make, model, year,)  #修改之后
        self.battery_size = 75
    def describe_battery(self):
        print(f"This car has a {self.battery_size}-kw battery")

my_tesla = ElectricCar('tesla', 'model s', 2019)
print(my_tesla.get_descriptive_name())
my_tesla.describe_battery()

输出结果为：

2019 Tesla Model S
This car has a 75-kw battery

Process finished with exit code 0

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