Question

If I have an assert in a unittest.TestCase as shown below:

self.assertTrue( person.age == 42, "age incorrect")

When it fails, it gives the “age incorrect” message. What I would also like to see is the expected and actual values. What’s the best way to go about doing this? Is it something unittest can do?

EDIT
I would like to see something like:

“age incorrect: expected value 42 actual value 39”

Answer 1

You should use a workaround to this problem, like this:

self.assertEqual(person.age, 42, 'age incorrect: expected value {0} actual value {1}'.format(42, person.age))

But i think not providing the “msg” parameter is the best option, since it generates the text:

first != equal

Most(*) tools for running tests also shows directly which line failed, thus you should be able to understand which test failed and why without using an extra message.

(*) read “all”.