simple retry decorator with exp backoff

retry_decorator.py

import time
import sys

def exp_backoff_retry(
    fun=None,
    *,
    retry_exceptions=(BaseException,),
    max_retries=3,
    exp_base=2.0,
    max_seconds=300,
):
    """
    Simple timeout decorator. Use eg. backoff for more proper one

    Kwargs:
        retry_exceptions: tuple of exceptions to catch and retry, by default any exception causes retry
                          except NameError, SyntaxError and ImportError
        max_retries: maximum number of retries
        exp_base: base for exponent in backoff delay. Defaults to 2
        max_seconds: maximum total time for retries in seconds. Defaults to 300
    """

    def decor(orig_fun):
        def log(msg):
            sys.stderr.write(f"{msg}\n")

        def inner(*args, **kwargs):
            start_t = time.time()
            retries = 0

            while True:
                try:
                    return orig_fun(*args, **kwargs)
                except (NameError, SyntaxError, ImportError):
                    raise
                except retry_exceptions as exc:
                    if retries >= max_retries:
                        log(f"Max retries of {max_retries} reached, raising")
                        raise

                    delay = exp_base ** retries

                    # If we have taken only 2 seconds, next sleep is for 4 seconds but max_seconds is 5,
                    # we can already give up as 2+4 > 5
                    if time.time() - start_t + delay > max_seconds:
                        log(f"Max time of {max_seconds:.3f} reached, raising")
                        raise

                    retries += 1

                    log(
                        f"Caught exception {exc}, attempt {retries}/{max_retries} in {delay:.3f}s"
                    )
                    time.sleep(delay)

        return inner

    if fun:
        return decor(fun)
    return decor