Python Circle Class With Getter Setter Methods

Python Circle Class With Getter Setter. In this Python programming tutorial we will learn about the use of Getter and Setter methods. How can we provide a getter and setter method for each variable in a Python class?

What are Getter and Setter Methods in Python class?

A getter method is actually an Accessor Method that returns the value of an instance variable. While a Setter method is also called a Mutator method. It is used to set the value of an instance variable in a Python class.

How to Create Circle Class?

Write a Python program to design a Circle class  with radius. Define a  constructor,  a setter setRadius() and a getter getRadius(). Write down a method to calculate area and the other method for perimeter:  findArea() and findPerimeter().

Design the Circle Class

class Circle:
    ''' Circle class'''

Define constructor for Circle Class

# constructor

    def __init__(self, radius):
        self.radius = radius

Writing Accessor and Mutator Methods for radius of Circle

Here we will define getRadius() and setRadius() methods for the instance variable “radius”.

The getRadius () method will return the value of radius.

On the other hand we can set or change the value of radius using setRadius() method. It will take a parameter which will provide the value to the associated instance variable.

# Write getter and setter for radius

    def setRadius(self,radius):
        self.radius = radius
    def getRadius(self):
        return self.radius

Define Methods To Calculate area and perimeter of  Circle

# write findArea() and findPerimeter()

    def findArea(self):
        return math.pi * self.radius * self.radius
    
    def findPerimeter(self):
        return 2*math.pi*self.radius

Source code of class Circle with Getter and Setter Methods

# Write a Python program to
# design a Circle class
# with radius,
# constructor,
# setRadius() and getRadius(),
# findArea() and findPerimeter()

import math
class Circle:
    ''' Circle class'''

# constructor

    def __init__(self, radius):
        self.radius = radius
        
# Write getter and setter for radius

    def setRadius(self,radius):
        self.radius = radius
    def getRadius(self):
        return self.radius
    
# write findArea() and findPerimeter()

    def findArea(self):
        return math.pi * self.radius * self.radius
    
    def findPerimeter(self):
        return 2*math.pi*self.radius

#  write main function

def  main():
    # create an object
    c1 = Circle(4.50)
    # show area and perimeter
    ar = c1.findArea()
    ar = round(ar,2)
    pe = c1.findPerimeter()
    pe = round(pe,2)
    
    # get radius
    r = c1.getRadius()
    
    print("Circle object c1 with radius=",r)
    print("Area = ", ar)
    print("Perimeter = ",pe)

    # set radius / change radius
    c1.setRadius(9.2456)

    # show area and perimeter for new value of radius
    ar = c1.findArea()
    ar = round(ar,2)
    r = c1.getRadius()
    #r = round(r,2)
    
    pe = c1.findPerimeter()
    pe = round(pe,2)

    print("Circle object c1 with radius=",r)
    print("Area = ", ar)
    print("Perimeter = ",pe)
        

# call main
main()

Circle object c1 with radius= 4.5
Area =  63.62
Perimeter =  28.27
Circle object c1 with radius= 9.2456
Area =  268.55
Perimeter =  58.09

Second Execution

Circle object c1 with radius= 2.54
Area =  20.27
Perimeter =  15.96
Circle object c1 with radius= 5.26
Area =  86.92
Perimeter =  33.05