run code when unit test assert fails [closed]

Question

I'm using assertEquals() from unittest.TestCase. What I want to do now is to call a function and do something there when the assertion fails, I wonder if there's a way of doing this?

Answer 1

In general you shouldn't do it, but if you really want to, here is a simple example:

import unittest

def testFailed():
    print("test failed")

class T(unittest.TestCase):
    def test_x(self):
        try:
            self.assertTrue(False)
        except AssertionError:
            testFailed()
            raise

if __name__ == "__main__":
    suite = unittest.defaultTestLoader.loadTestsFromTestCase(T)
    unittest.TextTestRunner().run(suite)

Another, more generic possibility is to write your own runTest method (as mentioned in the documentation) which will wrap all tests with try/except block. This would be even more recommended if you really need to do it, as it will keep your test code clean.