Python练习题 类的继承

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 + ' ' + self.model
return long_name.title()
def read_odometer(self):
print("This car has " + str(self.odometer_reading) + " miles on it.")
def update_odometer(self, mileage):
if mileage >= self.odometer_reading:
self.odometer_reading = mileage
else:
print("You can't roll back an odometer!")
def increment_odometer(self, miles):
self.odometer_reading += miles
def fill_gas_tank(self):
print("This car doesn't need a gas tank!")

class ElectricCar(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.")
def fill_gas_tank(self):
print("This car  need a gas tank!")
my_tesla=ElectricCar('tesla','model',2016)
print(my_tesla.get_descriptive_name())
my_tesla.describe_battery()
my_tesla.fill_gas_tank()