When a long suite of tests is running, it would be nice to be able to exit out early to see the results of the tests that have run so far.  I would like to see a couple of features included in `unittest` to this effect that have recently been implemented in django's test runner.  The first exits gracefully on `^C`, the second allows the user to specify a `--failfast` option, which causes the test runner to exit after the first failure or error, rather than proceeding with the If you hit `^C`, rather than exit with a stack trace of whatever was happening at the time, `unittest` should complete the current test, and then exit with the results to that point.  A second `^C` would be treated as a normal `KeyboardInterrupt`, in case that last test were somehow running on too long.{{{  $ python test_module.py..F.s.^C <Test run halted by Ctrl-C> x======================================================================FAIL: test_multiline_equal (__main__.MyTest)Unicode objects return diffs on failure----------------------------------------------------------------------Traceback (most recent call last):  File "test_test.py", line 39, in test_multiline_equal    self.assertEqual(original, revised)AssertionError: - Lorem ipsum dolor sit amet, ?             ^+ Lorem ipsum color sit amet, ?             ^              consectetur adipisicing elit, +             that's the way the cookie crumbles,              sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.----------------------------------------------------------------------Ran 7 tests in 12.010sFAILED (failures=1, skipped=1, expected failures=1)}}}A `failfast` option could be specified as a keyword argument to `unittest.main()`, or `unittest.main()` could read it off the command line, according to the same mechanism used by, e.g., the `verbosity` option.

This feature was implemented in the django test runner as [r12034](http://code.djangoproject.com/changeset/12034) (^C override) and [r11843](http://code.djangoproject.com/changeset/11843) (failfast option)

fwiw, the similarissue2241 was rejected two years ago.

I like the feature. I'm a bit concerned about the proliferation of command line options for unittest though. Steve's rejection of the feature seemed to be on the basis that he didn't need it (or see a need for it). :-)

Failfast option added, committedrevision 79265. Still needs documentation. Ctrl-C handling not yet done. Slightly more complex as it needs to play well with tests that test SIGINT handling.

Ctrl-C handling now implemented (-c command line option). Still needs documentation, but there is a bunch of this outstanding and I will do it in one go and rework the unittest docs at the same time.