test_logging.py 文件源码

def test_warnings(self):
        with warnings.catch_warnings():
            logging.captureWarnings(True)
            self.addCleanup(logging.captureWarnings, False)
            warnings.filterwarnings("always", category=UserWarning)
            stream = io.StringIO()
            h = logging.StreamHandler(stream)
            logger = logging.getLogger("py.warnings")
            logger.addHandler(h)
            warnings.warn("I'm warning you...")
            logger.removeHandler(h)
            s = stream.getvalue()
            h.close()
            self.assertTrue(s.find("UserWarning: I'm warning you...\n") > 0)

            #See if an explicit file uses the original implementation
            a_file = io.StringIO()
            warnings.showwarning("Explicit", UserWarning, "dummy.py", 42,
                                 a_file, "Dummy line")
            s = a_file.getvalue()
            a_file.close()
            self.assertEqual(s,
                "dummy.py:42: UserWarning: Explicit\n  Dummy line\n")