#!/usr/bin/env python3

import numpy as np

#------------------------ Circle class ----------------------

# Create a class named Circle that takes as input a radius when it is created, and has two methods, one that

# returns the area of the circle, the other that returns the perimeter. Write code to create two circles, one with

# radius 1 and one with radius 2 and print out their area and circumference

#

# [optional-fancy] If you stick the two class instances in a list, you can print them both out with a for loop...

# ----------------- Answers --------------------------------

class Circle:

"""

A 2d circle.

"""

def __init__(self, radius):

"""

Constructor.

:param radius: The circle radius.

"""

# We're not going to allow a negative radius.

if radius < 0:

raise ValueError('Circle: Radius must be non-negative')

self.radius = radius

def __str__(self):

return 'Circle({0})'.format(self.radius)

def area(self):

"""

Circle radius.

:return: The radius of the circle.

"""

return np.pi * self.radius ** 2

def circumference(self):

"""

The circumference of the circle.

:return: The circle circumference.

"""

return 2 * np.pi * self.radius

if __name__ == '__main__':

c1 = Circle(1.0)

c2 = Circle(2.0)

# Since the circles are just... objects, we can stick them in a list

shapes = [c1, c2]

for s in shapes:

print(f"{s}: area is {s.area():0.2f}, circumference is {s.circumference():0.2f}")