The relationship between parent and child classes / inheritance

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
@File: inheritance relationship .py _ parent class and subclass    
@ E-mail: [email protected]
@Time: 2020/4/4 12:39 AM 
@Author:Nobita   
@Version:1.0   
@Desciption: the relationship between parent and child classes / inheritance
"""


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

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

    DEF read_meter (Self):   # read several kilometers method 
        Print ( ' This CAR have have ' + STR (self.meter) + ' mi The ' )

    DEF update_meter (Self, mileage):   # defines a method to modify several kilometers, several kilometers to be modified after time, there is no need to modify the value of the property by way of example 
        self.meter = mileage

    DEF increment_meter (Self, Miles):   # newly added several kilometers do adder 
        self.meter + = Miles


my_car = Car('china', 'audi', '2010')

Print (my_car.model)
 Print (my_car.get_car_description () title ().)   # title method syntax -> str.title () // returns "title" of the string, that all words are capitalized to begin. 
my_car.read_meter ()
my_car.meter = 50   # by way of example of attribute values do change 
my_car.read_meter ()
my_car.update_meter ( 100)   # modify the value of the property by the previously defined method 
my_car.read_meter ()
my_car.increment_meter(200)
my_car.read_meter()


class Battery():
    def __init__(self, battery_size=70):
        self.battery_size = battery_size

    DEF describe_battery (Self):
         Print ( ' the car ' + STR (self.battery_size) + ' capacitance ' )

    def get_range(self):
        if self.battery_size == 70:
            car_range = 240
        elif self.battery_size <= 100 and self.battery_size >= 75:
            car_range = 270 
        MSG = ' the car can run km {} ' .format (car_range)
         return MSG


class ElectricCar (Car):   # create ElectricCar (electric vehicle) class 
    DEF  __init__ (Self, the make, Model, year):
        super().__init__(make, model, year)
        self.battery = Battery()

    DEF describe_battery (Self):
         Print ( ' electric vehicle specific attributes} is { ' .format (self.battery.battery_size))

    DEF read_meter (Self):
         # a parent class among, subclass does not help; in subclasses among them the definition of a parent class with the name of the method name, it will ignore the parent class method, its essence. (Method override the parent class) 
        Print ( " This method is a method to rewrite the parent class, ignores read_meter () method of the parent class from among ' )


my_ele_car = ElectricCar ( ' use ' , ' Baoma ' , ' 2020 ' )

print(my_ele_car.get_car_description().title())
my_ele_car.read_meter()
my_ele_car.describe_battery()
my_ele_car.battery.describe_battery()
print(my_ele_car.battery.battery_size)
print(my_ele_car.battery.get_range())
my_ele_car.battery.battery_size = 80   # by way of example of attribute values do change 
Print (my_ele_car.battery.get_range ())

'''
super () is a special function that allows parent and child classes can be associated.
This code allows python to call ElectricCar parent class method __init __ (), so that ElectricCar instance contains all the properties of the parent class.
Python class initialization method is the __init __ (), so the parent class, subclass initialization method is that,
If a subclass does not implement __init __ () function is called to initialize the parent class initialization,
If the child class implements this function, this function will have to explicitly call it in the parent class __init __ (),
This is with C ++, jAVA do not, they are automatically call the parent class constructor.
'''