Mocking Python Files

Just a quick note on testing python; I needed to test a method the reads in from a file. To do that I could either created a temp file or use stringio. Stringio is easier and quicker so I used that, here's how:

def mockfile(text):
    return StringIO.StringIO(text)

class Tester1(unittest.TestCase):
    def setUp(self):
        self.filehandle = mockfile("""
        gen , G1  , 101 , 450  ,  50  ,   U20""")
        self.components = read(self.filehandle)

    def tearDown(self):
        self.filehandle.close()
        self.filehandle = None
        self.components = None

    def test_name(self):
        self.assertEqual(set(self.components.keys()), 
                         set("G1"))


class Tester2(unittest.TestCase):
    def test_a(self):
        components = read(mockfile(""))
        self.assertEqual(len(components),0)

Hopefully I this is the first in a series of posts on practical TDD. Watch this space