# Simple version:
import sys, time
class RetryError(Exception):
pass
def retryloop(attempts, timeout):
starttime = time.time()
success = set()
for i in range(attempts):
success.add(True)
yield success.clear
if success:
return
if starttime + timeout < time.time():
break
raise RetryError
"""
Usage:
for retry in retryloop(10, timeout=30):
try:
something
except SomeException:
retry()
for retry in retryloop(10, timeout=30):
something
if somecondition:
retry()
"""
# Fancy version:
def fancyretryloop(attempts, timeout=None, delay=0, backoff=1):
starttime = time.time()
success = set()
for i in range(attempts):
success.add(True)
yield success.clear
if success:
return
duration = time.time() - starttime
if timeout is not None and duration > timeout:
break
if delay:
time.sleep(delay)
delay = delay * backoff
e = sys.exc_info()[1]
# No pending exception? Make one
if e is None:
try: raise RetryError
except RetryError as e: pass
# Decorate exception with retry information:
e.args = e.args + ("on attempt {0} of {1} after {2:.3f} seconds".format(i, attempts + 1, duration),)
raise
