为什么错误说 Object has no attribute？ [复制]

Question

我已经多次查看此代码，但我无法找出为什么错误一直在说

    print("This car has a " + str(self.battery_size) + "-kWh battery.")
AttributeError: 'Electric' object has no attribute 'battery_size'

class Car:
    def __init__(self, make, model, year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        long_name = str(self.year) +' '+self.make.title()+' ' + self.model.title()
        return long_name.title()

    def read_odometer(self):
        print("the car ran " + str(self.odometer_reading) + " miles ")

    def update_odometer(self, milage):
        self.odometer_reading += milage
        print("odo meter reading is "+str(self.odometer_reading))

class Electric(Car):
    def _init_(self, make, model, year):
        super().__init__(make, model, year)
        self.battery_size = 70

    def describe_battery(self):
        print("This car has a " + str(self.battery_size) + "-kWh battery.")

my_tesla = Electric('tesla', 'model s', '2016')
print(my_tesla.get_descriptive_name())
my_tesla.describe_battery()

任何帮助将不胜感激。 谢谢

Answer 1

应该是：

class Electric(Car):
    def __init__(self, make, model, year):

两个下划线。