simple_retry_v1.py

from functools import wraps

import gevent
import six

class DoRetry(object):

    def __init__(self, times=2, interval=5, exponential_interval=True):
        if not (interval > 0 and isinstance(times, int) and times > 0):
            raise AttributeError('interval and times must be a positive')
        self.times = times
        self.interval = interval
        self.is_exponential = exponential_interval

    def __call__(self, func, *args, **kwargs):
        @wraps(func)
        def wrap(*args, **kwargs):
            try_after = 0
            elapsed = 0
            while True:
                elapsed += 1
                gevent.sleep(try_after)
                try:
                    retval = func(*args, **kwargs)
                    break
                except Exception as e:
                    if self.times > elapsed:
                        if self.is_exponential:
                            try_after = self.interval ** elapsed
                        else:
                            try_after = self.interval
                    else:
                        ret = 'failed after %s %s' % (elapsed, 'try' if elapsed <= 1 else 'tries')
                        ex = RuntimeError(ret)
                        six.raise_from(e, ex)
            return retval
        return wrap


@DoRetry(3, 3)
def function_fails_forever(**kwargs):
    raise ValueError("throwing a ValueError intentionally")


@DoRetry(3, 3)
def function_that_succeeds(**kwargs):
    print("We are good")
    return kwargs


if __name__ == '__main__':
    threads = [gevent.spawn(function_fails_forever), gevent.spawn(function_that_succeeds)]
    gevent.joinall(threads)