test_fileio.py 文件源码

def testBadModeArgument(self):
        # verify that we get a sensible error message for bad mode argument
        bad_mode = "qwerty"
        try:
            f = _FileIO(TESTFN, bad_mode)
        except ValueError as msg:
            if msg.args[0] != 0:
                s = str(msg)
                if TESTFN in s or bad_mode not in s:
                    self.fail("bad error message for invalid mode: %s" % s)
            # if msg.args[0] == 0, we're probably on Windows where there may be
            # no obvious way to discover why open() failed.
        else:
            f.close()
            self.fail("no error for invalid mode: %s" % bad_mode)