testing stdout in python

test_stdout.py

import sys
from StringIO import StringIO
from unittest import TestCase

class Foo(object):
    
    def hello(self):
        print 'world'

class StdoutTest(TestCase):

    def setUp(self):
        self.output = StringIO()
        self.saved_stdout = sys.stdout
        sys.stdout = self.output
    
    def test_hello(self):
        
        obj = Foo()
        obj.hello()
        self.assertEqual(self.output.getvalue(), "world\n")

    def tearDown(self):
        self.output.close()
        sys.stdout = self.saved_stdout