Overloading constructor example

spike.py

class Greeter:
        def __init__(self, greeting=None):
                self.myGreeting = greeting or 'Hello World!'

        def greeting(self):
                return self.myGreeting

spiketests.py

import unittest
from spike import Greeter

class GreeterTest(unittest.TestCase):

        def test_greetingReturnsDefault(self):
                mw = Greeter()
                self.assertEqual(mw.greeting(),'Hello World!','greeting is not as expected')

        def test_greetingReturnsConstructorProvidedContent(self):
                mw = Greeter('booyah!')
                self.assertEqual(mw.greeting(),'booyah!')
		
if __name__ == '__main__':
        unittest.main()