log_file_name = os.path.join(
    os.environ.get('OPENSHIFT_PYTHON_LOG_DIR', '.'),
    'app.log')

handler = logging.FileHandler(log_file_name, mode='a')
handler.setLevel(logging.INFO)
fmt = "%(asctime)s\t%(message)s"
# 实例化formatter
formatter = logging.Formatter(fmt)
# 为handler添加formatter
handler.setFormatter(formatter)
app.logger.addHandler(handler)
app.logger.setLevel(logging.INFO)

logger = logging.getLogger('selfname')
fmter = logging.Formatter('%(asctime)s %(levelname)s %(message)s', datefmt='%a, %d %b %Y %H:%M:%S')
log_file_name = os.path.join(os.environ.get('OPENSHIFT_PYTHON_LOG_DIR', '.'),
                             'filename.log')
hdlr = logging.FileHandler(log_file_name, mode='a')
hdlr.setLevel(logging.INFO)
hdlr.setFormatter(fmter)
logger.addHandler(hdlr)
logger.setLevel(logging.INFO)