test_logging.py 文件源码

def test_rollover(self):
        fh = logging.handlers.TimedRotatingFileHandler(self.fn, 'S',
                                                       backupCount=1)
        fmt = logging.Formatter('%(asctime)s %(message)s')
        fh.setFormatter(fmt)
        r1 = logging.makeLogRecord({'msg': 'testing - initial'})
        fh.emit(r1)
        self.assertLogFile(self.fn)
        time.sleep(1.1)    # a little over a second ...
        r2 = logging.makeLogRecord({'msg': 'testing - after delay'})
        fh.emit(r2)
        fh.close()
        # At this point, we should have a recent rotated file which we
        # can test for the existence of. However, in practice, on some
        # machines which run really slowly, we don't know how far back
        # in time to go to look for the log file. So, we go back a fair
        # bit, and stop as soon as we see a rotated file. In theory this
        # could of course still fail, but the chances are lower.
        found = False
        now = datetime.datetime.now()
        GO_BACK = 5 * 60 # seconds
        for secs in range(GO_BACK):
            prev = now - datetime.timedelta(seconds=secs)
            fn = self.fn + prev.strftime(".%Y-%m-%d_%H-%M-%S")
            found = os.path.exists(fn)
            if found:
                self.rmfiles.append(fn)
                break
        msg = 'No rotated files found, went back %d seconds' % GO_BACK
        if not found:
            #print additional diagnostics
            dn, fn = os.path.split(self.fn)
            files = [f for f in os.listdir(dn) if f.startswith(fn)]
            print('Test time: %s' % now.strftime("%Y-%m-%d %H-%M-%S"), file=sys.stderr)
            print('The only matching files are: %s' % files, file=sys.stderr)
            for f in files:
                print('Contents of %s:' % f)
                path = os.path.join(dn, f)
                with open(path, 'r') as tf:
                    print(tf.read())
        self.assertTrue(found, msg=msg)