Question

Python: Using Inheritance to Create a Derived Class in Python

In this lab, you create a derived class from a base class, and then use the derived class in a Python program. The program should create two Motorcycle objects, and then set the Motorcycle’s speed, accelerate the Motorcycle object, and check its sidecar status.

Instructions

1. Open the file named Motorcycle.py.
2. Create the Motorcycle class by deriving it from the Vehicle class. Use a public derivation.
3. In the Motorcycle class, create an attribute named sidecar.
4. Write a public set method to set the value for sidecar.
5. Write a public get method to retrieve the value of sidecar.
6. Write a public accelerate method. This method overrides the accelerate method inherited from the Vehicle class. Change the message in the accelerate method so the following is displayed when the Motorcycle tries to accelerate beyond its maximum speed: "This motorcycle cannot go that fast".
7. Open the file named MyMotorcycleClassProgram.py.
8. In the MyMotorcycleClassProgram, there are two Motorcycle objects named motorcycleOne and motorcycleTwo.
9. Set the sidecar value of motorcycleOne to true and the sidecar value of motorcycleTwo to false.
10. Set motorcycleOne’s maximum speed to 90 and motorcycleTwo’s maximum speed to 85.
11. Set motorcycleOne’s current speed to 65 and motorcycleTwo’s current speed to 60.
12. Accelerate motorcycleOne by 30 mph, and accelerate motorcycleTwo by 20 mph.
13. Print the current speed of motorcycleOne and motorcycleTwo.
14. Determine if motorcycleOne and motorcycleTwo have sidecars. If yes, display the following: "This motorcycle has a sidecar". If not, display the following: "This motorcycle does not have a sidecar".
15. Execute the program.

Answer 1

motorcycle.py:

#Vehicle is a parent class
class Vehicle:
def accelarate(self,a):
print(a)
#Motorcycle is child class inherits vehicle class
class Motorcycle(Vehicle):
def __init__(self):
self.maxSpeed=0
self.currentSpeed=0
self.sidecar=True
#setMethod is used to set sidecar value
def setMethod(self,x):
self.sidecar=x
#getMethod is used to retrieve sidecar value
def getMethod(self):
return self.sidecar
#accelerate method is used to set accceleration
def accelerate(self,a):
if (self.currentSpeed + a ) > self.maxSpeed:
print("This motorcycle cannot go that fast")
else:
self.currentSpeed += a
#This is the get method to find the current speed
def findSpeed(self):
return self.currentSpeed
#This method is used to check sidecar status
def checkSideCar(self):
if self.sidecar:
print("This motorcycle has a sidecar")
else:
print("This motorcycle does not have a sidecar")

MyMotorcycleClassProgram.py:

#Motorcycle is imported from motorcycle.py
from motorcycle import Motorcycle

#motorcycle objects are created
motorcycleOne=Motorcycle()
motorcycleTwo=Motorcycle()

#to set the sidecar value
motorcycleOne.setMethod(True)
motorcycleTwo.setMethod(False)

#to set the maximum speed of motorcycle
motorcycleOne.maxSpeed=90
motorcycleTwo.maxSpeed=85

#to set the speed of motorcycle
motorcycleOne.currentSpeed=65
motorcycleTwo.currentSpeed=60

#to set the acceleration of motorcycle
motorcycleOne.accelerate(30)
motorcycleTwo.accelerate(20)

print("The speed of motorcycleOne : ",motorcycleOne.findSpeed())
print("The speed of motorcycleTwo : ",motorcycleTwo.findSpeed())

motorcycleOne.checkSideCar()
motorcycleTwo.checkSideCar()

Output:

This motorcycle cannot go that fast
The speed of motorcycleOne : 65
The speed of motorcycleTwo : 80
This motorcycle has a sidecar
This motorcycle does not have a sidecar