test_deprecate.py 文件源码

def test_filteredOnceWarning(self):
        """
        L{deprecate.warnAboutFunction} emits a warning that will be filtered
        once if L{warnings.filterwarning} is called with the module name of the
        deprecated function and an action of once.
        """
        # Clean up anything *else* that might spuriously filter out the warning,
        # such as the "always" simplefilter set up by unittest._collectWarnings.
        # We'll also rely on trial to restore the original filters afterwards.
        del warnings.filters[:]

        warnings.filterwarnings(
            action="module", module="twisted_private_helper")

        from twisted_private_helper import module
        module.callTestFunction()
        module.callTestFunction()

        warningsShown = self.flushWarnings()
        self.assertEqual(len(warningsShown), 1)
        message = warningsShown[0]['message']
        category = warningsShown[0]['category']
        filename = warningsShown[0]['filename']
        lineno = warningsShown[0]['lineno']
        msg = warnings.formatwarning(message, category, filename, lineno)
        self.assertTrue(
            msg.endswith("module.py:9: DeprecationWarning: A Warning String\n"
                         "  return a\n"),
            "Unexpected warning string: %r" % (msg,))