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Python3 关于类的学习

Python3 关于类的学习

作者: 半场_64dd | 来源:发表于2018-10-05 19:33 被阅读0次

    #!/usr/bin/python3

    import _thread

    import time

    ##class Dog():

    ##        def __init__(self,name,age):

    ##                self.name = name

    ##                self.age = age

    ##        def sit(self):

    ##                print(self.name.title() + "is now sitting")

    ##        def roll_over(self):

    ##                print(self.name.title() + "rolled over!")

    ##my_dog = Dog('willie',6)

    ##print("My dog's name is " + my_dog.name )

    ##

    ### 为线程定义一个函数

    ##def print_time( threadName, delay):

    ##   count = 0

    ##   while count < 20:

    ##      time.sleep(delay)

    ##      count += 1

    ##      print ("%s: %s\r\n" % ( threadName, time.ctime(time.time()) ))

    ##

    ### 创建两个线程

    ##try:

    ##   _thread.start_new_thread( print_time, ("Thread-1", 2, ) )

    ##   _thread.start_new_thread( print_time, ("Thread-2", 2, ) )

    ##except:

    ##   print ("Error: 无法启动线程")

    ##

    ##while 1:

    ##   pass

    ##2018年10月5日13:44:32

    #2018年10月5日13:44:32

    """Python关于类(Class)的学习"""

    class Dog():

        """一次模拟小狗的简单尝试"""

        def __init__(self,name,age):

            self.name = name

            self.age = age

        def sit(self):

            """模拟小狗被命令时蹲下"""

            print(self.name.title() + " is now sitting.")

        def roll_over(self):

            """模拟小狗被命令时打滚"""

            print(self.name.title() + " rolled over!")

    """根据类创建实例并访问类的属性"""

    my_dog = Dog('willie',6)

    print("My dog's name is " + my_dog.name.title() + ".")

    print("My dog is " + str(my_dog.age) + " years old.")

    """调用方法"""

    my_dog.sit()

    my_dog.roll_over()

    """动手试一试"""

    class Restaurant():

        def __init__(self,restaurant_name,cuisine_type):

            self.resname = restaurant_name

            self.cuistype = cuisine_type

        def describe_restaurant(self):

            print(self.resname + " is the restaurant name.")

            print(self.cuistype + " is the restaurant cuisine_type")

        def open_restaurant(self):

            print("The restaurant is open now")

    myrestaurant = Restaurant("Spicy way","Chinese food")

    myrestaurant.describe_restaurant()

    myrestaurant.open_restaurant()

    res1 = Restaurant("Zuoxiangyoulin","XiangCai")

    res2 = Restaurant("Aiwanting","XiangCai")

    res3 = Restaurant("Lanzhoufood","Lanzhou")

    res1.describe_restaurant()

    res2.describe_restaurant()

    res3.describe_restaurant()

    class User():

        def __init__(self,first_name,last_name,age,grade,professional):

            self.first_name = first_name

            self.last_name = last_name

            self.age = age

            self.grade = grade

            self.professional = professional

        def describe_user(self):

            print(self.first_name + " is My First_name.")

            print(self.last_name + " is  My Last_nme.")

            print("My age is " + self.age + ".")

            print("My grade is " + self.grade + ".")

            print(self.professional + " is my job.")

        def great_user(self):

            print("Welcome, "+ self.first_name + self.last_name + " nice to meet you!")

    stu1 = User("Pan","Yan","22","Male","Engineer")

    stu1.describe_user()

    stu1.great_user()

    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 = 0

        def get_descriptive_name(self):

            """返回整洁的描述性信息"""

            long_name = str(self.year) + ' ' + self.make + ' ' + self.model

            ##long_name = 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 updata_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):

            if miles >= 0:

                self.odometer_reading += miles

            else:

                print("You can't set an miles with  negative increments")

        def fill_gas_tank(self,gallon):

            print("The car have "+ str(gallon) + ' capacity')

    ##9.3.5 将实例用作属性

    class Battery():

        def __init__(self,battery_size=70):

            self.battery_size = battery_size+10

        def describe_battery(self):

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

    class ElectricCar(Car):

        def __init__(self,make,model,year):

            super().__init__(make,model,year)

            self.battery = Battery()

    ##    def describe_battery(self):

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

        def fill_gas_tank(self,gallon):

            print("This car doesn't need a gas tank!")

    my_tesla = ElectricCar('tesla','model s',2016)

    print(my_tesla.get_descriptive_name())

    my_tesla.battery.describe_battery()

    my_tesla.fill_gas_tank(20)

    my_new_car = Car('andi','a4',2016)

    print(my_new_car.get_descriptive_name())

    my_new_car.read_odometer()

    my_new_car.odometer_reading = 23

    my_new_car.read_odometer()

    my_new_car.updata_odometer(10)

    my_new_car.read_odometer()

    my_new_car.increment_odometer(100)

    my_new_car.read_odometer()

    创建和使用类

               ​class Dog():

    ###class        关键字

    ###Dog()ClassName一般首字母大写

                       方法 __init__()

    exp: __init__(self,name,age):

    ### __init__()称为方法,我们将方法__init__() 定义成了包含三个形参:self 、name 和age 。在这个方法的定义中,形参self 必不可少,还必须位于其他形参的前面。为何必须在方法定义中包含形参self 呢?因为Python调用这个__init__() 方法来创建Dog 实例时,将自动传入实参self 。每个与类相关联的方法调用都自动传递实参self ,它是一个指向实例本身的引用,让实例能够访问类中的属性和方法。我们创建Dog 实例时,Python将调用Dog 类的方法__init__() 。我们将通过实参向Dog() 传递名字和年龄;self 会自动传递,因此我们不需要传递它。每当我们根据Dog 类创建实例时,都只需给最后两个形参(name 和age )提供值。

    self.name = name

    self.age = age

    ###以self为前缀的变量都可供类中的所有方法使用,我们还可以通过类的任何实例来访问这些变量。可通过实例访问到的变量称为属性

    my_dog = Dog('Hole',6)

    my_dog.name###要访问实例的属性,可以使用句点表示法。

    调用方法

    my_dog.sit()

    my_dog.roll_over()###实例名称+'.'+方法。

    在class Car里面,我们给类中的每个属性制定初始值,

    修改属性的值

    1.直接修改属性的值。

    2.通过方法修改属性的值

    继承

    ​class Car():

    class ElectricCar(Car):

        def __init__(self,make,model,year):

             super().__init__(make,model,year)

    父类必须位于子类的前面,定义子类时,必须在括号内指定父类名称。

    使用super()函数将父类和子类关联起来,

    当子类有某个属性与父类不一致时,譬如小汽车和电动汽车,电动汽车没有油箱,我们可以通过重写父类的方法,给子类写一个和父类重名的方法。使子类的该属性值不冲父类处继承。

    将实例用作属性

    使用代码模拟实物时,属性和方法的文件都越来越长,可以将类的一部分作为一个独立的类提取出来。

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