import time from functools import wraps # https://www.saltycrane.com/blog/2009/11/trying-out-retry-decorator-python/ def retry(ExceptionToCheck, tries=2, delay=1, backoff=1, logger=None): """ Retry calling the decorated function using an exponential backoff. http://www.saltycrane.com/blog/2009/11/trying-out-retry-decorator-python/ original from: http://wiki.python.org/moin/PythonDecoratorLibrary#Retry :param ExceptionToCheck: the exception to check. may be a tuple of exceptions to check :type ExceptionToCheck: Exception or tuple :param tries: number of times to try (not retry) before giving up :type tries: int :param delay: initial delay between retries in seconds :type delay: int :param backoff: backoff multiplier e.g. value of 2 will double the delay each retry :type backoff: int :param logger: logger to use. If None, print :type logger: logging.Logger instance """ def deco_retry(f): @wraps(f) def f_retry(*args, **kwargs): mtries, mdelay = tries, delay while mtries > 1: try: return f(*args, **kwargs) except ExceptionToCheck as e: msg = "%s, Retrying in %d seconds..." % (str(e), mdelay) if logger: logger.warning(msg) else: print(msg) time.sleep(mdelay) mtries -= 1 mdelay *= backoff return f(*args, **kwargs) return f_retry # true decorator return deco_retry