a test for if an instance was created

Ok,  I tried to put comments in to explain it. 

********* first the file that holds the class's and methods ***********

example.py

class Example(object):

# this is just for testing. I want to show how you can test it.

def print_something(self):

# def a string to return for test...

some_string = "I am going to make this work"

#return that string, could be anything

return some_string

class MakeSomething(object):

# we are going to give the instance of MakeSomething two

# attributes when it's initiated. A name and a dictionary

# which will hold the call for our Example class when we

# create it.

def __init__(self, name):

# the has has an attribute, name which you pass

# in with the paramaters makesomething = MakeSomething('name')

# it also has a dictionary named routes, that belongs to only

# the class MakeSomething, and the instance you create

self.name = name

self.routes = {}

# this will return a value for direction, which in this

# case we're going to make an instance of class Example further down

def go(self, direction):

return self.routes.get(direction, None)

# we are going to add a 'route' to the routes that can

# take you to a different instance, in this case an instance

# of Example class

def add_route(self, routes):

self.routes.update(routes)

# lets make an instance of MakeSomething....

# give it a name

makesomething = MakeSomething('a_place')

# lets add a route that will take us to the Example,

# when we type 'Example()' that creates an instance and runs

# the code inside.

makesomething.add_route({

'go to example': Example()

})

Now the file that holds the test. This test works on nosetest or pytest.

*********example_test.py**********

from nose.tools import*

from example import*

# we import the stuff we are testing to the file we test

def test_example():

# What this is doing is saying that our 'makesomething'

# is an instance of the MakeSomething class/object type

assert_true(isinstance(makesomething, MakeSomething))

# now we're going to see if makesomething will make an

# instance of example like we wanted.

gosomewhere = makesomething.go('go to example')

# lest see if that triggered the 'Example()' instance

assert_true(isinstance(gosomewhere, Example))

# and we can test that the Example.print_something returns a string

assert_true(isinstance(gosomewhere.print_something(), str))