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Python

Nancy Melucci
PLUS
Nancy Melucci
Courses Plus Student 35,157 Points
Posted by Nancy Melucci
Nancy Melucci
Courses Plus Student 35,157 Points

Python string function "bound method" output instead of values.

I wrote a simple Circle class in Python with methods that work and produce correct values (I think). I need to write a str function to output the characteristics of the circle and when I call the attributes and method results I get the following output...

201.06192982974676 50.26548245743669 16 The circle has radius 8 with an area of <bound method Circle.area of <Circle.Circle object at 0x0000000002D1C518>>and a diameter of <bound method Circle.diameter of <Circle.Circle object at 0x0000000002D1C518>> and a circumference of <bound method Circle.circumference of <Circle.Circle object at 0x0000000002D1C518>>

How do I make that stop and replace it with the actual values? Code of class and instantiation follows...

Thank you.

import math


class Circle():
    def __init__(self, r):
        self.radius = r

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

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

    def diameter(self):
        return 2*self.radius

    def __str__(self):
        return "The circle has radius " + str(self.radius) + " with an area of  " + str(self.area) + "and a diameter of " + str(self.diameter) + " and a circumference of " + str(self.circumference)

from Circle import Circle
import math


c1 = Circle(8)
print(c1.area())
print(c1.circumference())
print(c1.diameter())
print(str(c1))

3 Answers

Chris Sederqvist
Chris Sederqvist
7,596 Points
Chris Sederqvist
Chris Sederqvist
7,596 Points

Add method calls:

def __str__(self):
    return "The circle has radius " + str(self.radius) + " with an area of " + str(self.area()) + " and a diameter of " + str(self.diameter()) + " and a circumference of " + str(self.circumference())

This fixes the output.

Chris Sederqvist
Chris Sederqvist
7,596 Points
Chris Sederqvist
Chris Sederqvist
7,596 Points

This formatting would appear with two decimal points:

def __str__(self):
        return "The circle has radius {0:.2f} with an area of {1:.2f} and a diameter of {2:.2f} and a circumference of {3:.2f}".format(self.radius, self.area(), self.diameter(), self.circumference())

For the print statements:

print("%.2f" % c1.area())
print("%.2f" % c1.circumference())
print("%.2f" % c1.diameter())

Good luck!

Nancy Melucci
PLUS
Nancy Melucci
Courses Plus Student 35,157 Points
Nancy Melucci
Nancy Melucci
Courses Plus Student 35,157 Points

Follow up question, if anyone is out there. Is there a way to format the diameter, area and circumference to two floating decimals?

Thanks.