在 Python 中使用继承创建派生类答案

【问题标题】：Using Inheritance to Create a Derived Class in Python在 Python 中使用继承创建派生类
【发布时间】：2018-04-01 22:05:29
【问题描述】：

从基类创建派生类，然后在 Python 程序中使用派生类。程序应该创建两个 Motorcycle 对象，然后设置 Motorcycle 的速度，加速 Motorcycle 对象，并检查它的 sidecar 状态。必须使用该类来运行以下类：

class Motorcycle: 

    maxspeed = 0
    minspeed = 0
    sidecar = ""

    def __init__(self, maxspeed, minspeed, sidecar):
        self.maxspeed = maxspeed
        self.minspeed = minspeed
        self.sidecar = sidecar
    def sidecar(self):
        self.get_sidecar = True
        return self.get_sidecar
    def speed(self, speed):
        self.speed = self.minspeed + self.accelerate
        return self.speed

    def accelerate(self, accelerate):
        self.accelerate = accelerate
        if (self.accelerate + self.minspeed) > self.maxspeed:
            print("This motorcycle cannot go that fast")

下课：

from Motorcycle import Motorcycle

motorcycleOne = Motorcycle(90.0, 65.0, True)
motorcycleTwo = Motorcycle(85.0, 60.0, False)

motorcycleOne.accelerate(30.0)
motorcycleTwo.accelerate(20.0)

print("The current speed of motorcycleOne is " + str(motorcycleOne.speed))
print("The current speed of motorcycleTwo is " + str(motorcycleTwo.speed))

if motorcycleOne.sidecar:
   print("This motorcycle has a sidecar")
else:
   print("This motorcycle does not have a sidecar")

if motorcycleTwo.sidecar:
   print("This motorcycle has a sidecar")
else:
   print("This motorcycle does not have a sidecar")

我不断收到这条消息以检索速度：绑定方法...... 如果有人可以提供任何建议，我不知道从哪里开始，我将不胜感激。

【问题讨论】：

标签： python class object inheritance

【解决方案1】：

您正在混合属性和方法。您的“速度”应该是您的类的属性，而“加速”应该是修改该属性的方法。一些代码来说明我的意思。

class Motorcycle:

    def __init__(self, maxspeed, minspeed, sidecar):
        self.maxspeed = maxspeed
        self.minspeed = minspeed
        self.speed = minspeed # Initial speed is equal to minspeed
        self.sidecar = sidecar

    # Printing methods
    # Print sidecar status
    def has_sidecar(self):
        if self.sidecar:
            print("This motorcycle has a sidecar")
        else:
            print("This motorcycle does not have a sidecar")
    # Print speed
    def how_fast(self):
        print ("The current speed of this motorcycle is {}".format(self.speed))

    # Methods to change your sidecar status:
    def add_sidecar(self):
        self.sidecar = True
    def remove_sidecar(self):
        self.sidecar = False
    # Method to accelerate
    def accelerate(self, accelerate):
        if (self.speed + accelerate) > self.maxspeed:
            print("This motorcycle cannot go that fast")
        else:
            self.speed += accelerate

motorcycleOne = Motorcycle(90.0, 65.0, True)
motorcycleTwo = Motorcycle(85.0, 60.0, False)

motorcycleOne.accelerate(30.0)
motorcycleTwo.accelerate(20.0)

motorcycleOne.how_fast()
motorcycleTwo.how_fast()

motorcycleOne.has_sidecar()
motorcycleTwo.has_sidecar()

给予：

This motorcycle cannot go that fast
The current speed of this motorcycle is 65.0
The current speed of this motorcycle is 80.0
This motorcycle has a sidecar
This motorcycle does not have a sidecar

...

但是你不是从基类继承一个类。

【讨论】：

【解决方案2】：

speed 和 sidecar 都是方法；你需要给他们打电话。

print("The current speed of motorcycleOne is " + motorcycleOne.speed())

注意，您似乎没有按照说明创建基类和派生类。

【讨论】：