cpython/Lib/test/json_tests/__init__.py

import os
import sys
import unittest
import doctest

here = os.path.dirname(__file__)

def test_suite():
    suite = additional_tests()
    loader = unittest.TestLoader()
    for fn in os.listdir(here):
        if fn.startswith("test") and fn.endswith(".py"):
            modname = "test.json_tests." + fn[:-3]
            __import__(modname)
            module = sys.modules[modname]
            suite.addTests(loader.loadTestsFromModule(module))
    return suite

def additional_tests():
    import json
    import json.encoder
    import json.decoder
    suite = unittest.TestSuite()
    for mod in (json, json.encoder, json.decoder):
        suite.addTest(doctest.DocTestSuite(mod))
    return suite

def main():
    suite = test_suite()
    runner = unittest.TextTestRunner()
    runner.run(suite)

if __name__ == '__main__':
    sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
    main()