Fixed #6364 -- Added the ability to run individual doctests.

    if len(parts) < 2 or len(parts) > 3:

        raise ValueError("Test label '%s' should be of the form app.TestCase or app.TestCase.test_method" % label)

    #

    # First, look for TestCase instances with a name that matches

    #

    app_module = get_app(parts[0])

    test_module = get_tests(app_module)

    TestClass = getattr(app_module, parts[1], None)

    # Couldn't find the test class in models.py; look in tests.py

    if TestClass is None:

        test_module = get_tests(app_module)

        if test_module:

            TestClass = getattr(test_module, parts[1], None)

    try:

        if issubclass(TestClass, unittest.TestCase):

            print 'is a test case'

            if len(parts) == 2: # label is app.TestClass

                try:

                    return unittest.TestLoader().loadTestsFromTestCase(TestClass)

                except TypeError:

                    raise ValueError("Test label '%s' does not refer to a test class" % label)

            else: # label is app.TestClass.test_method

        if not TestClass:

            raise ValueError("Test label '%s' does not refer to a test class" % label)

                return TestClass(parts[2])

    except TypeError:

        # TestClass isn't a TestClass - it must be a method or normal class

        pass

    #

    # If there isn't a TestCase, look for a doctest that matches

    #

    tests = []

    for module in app_module, test_module:

        try:

            doctests = doctest.DocTestSuite(module,

                                            checker=doctestOutputChecker,

                                            runner=DocTestRunner)

            # Now iterate over the suite, looking for doctests whose name

            # matches the pattern that was given

            for test in doctests:

                if test._dt_test.name in (

                        '%s.%s' % (module.__name__, '.'.join(parts[1:])),

                        '%s.__test__.%s' % (module.__name__, '.'.join(parts[1:]))):

                    tests.append(test)

        except ValueError:

            # No doctests found.

            pass

    # If no tests were found, then we were given a bad test label.

    if not tests:

        raise ValueError("Test label '%s' does not refer to a test" % label)

    # Construct a suite out of the tests that matched.

    return unittest.TestSuite(tests)

# Python 2.3 compatibility: TestSuites were made iterable in 2.4.

# We need to iterate over them, so we add the missing method when

.. versionadded:: 1.0

   You can now choose which test to run.

If you use unit tests, as opposed to

doctests, you can be even *more* specific in choosing which tests to execute.

To run a single test case in an application (for example, the

``AnimalTestCase`` described in the "Writing unit tests" section), add the

name of the test case to the label on the command line::

You can be even *more* specific by naming an individual test case. To

run a single test case in an application (for example, the

``AnimalTestCase`` described in the "Writing unit tests" section), add

the name of the test case to the label on the command line::

    $ ./manage.py test animals.AnimalTestCase

And it gets even more granular than that! To run a *single* test method inside

a test case, add the name of the test method to the label::

And it gets even more granular than that! To run a *single* test

method inside a test case, add the name of the test method to the

label::

    $ ./manage.py test animals.AnimalTestCase.testFluffyAnimals

.. versionadded:: 1.2

   The ability to select individual doctests was added.

You can use the same rules if you're using doctests. Django will use the

test label as a path to the test method or class that you want to run.

If your ``models.py`` or ``tests.py`` has a function with a doctest, or

class with a class-level doctest, you can invoke that test by appending the

name of the test method or class to the label::

    $ ./manage.py test animals.classify

If you want to run the doctest for a specific method in a class, add the

name of the method to the label::

    $ ./manage.py test animals.Classifier.run

If you're using a ``__test__`` dictionary to specify doctests for a

module, Django will use the label as a key in the ``__test__`` dictionary

for defined in ``models.py`` and ``tests.py``.

.. versionadded:: 1.2

   You can now trigger a graceful exit from a test run by pressing ``Ctrl-C``.