exponential retry

max_retries = 5

try:
		do_stuff(objKey)
		
		except (somerror) as e:


			logger.error('got a timeout for %s -> %s', objKey, e)
		
			#
			#retry until we either succeed, or reach max_retries
			#
			
			for attempt in range(max_retries):
				#
				#exponential backoff
				#
				print "sleeping for %s secs before retry" %(2 ** attempt) 
				time.sleep(2 ** attempt)

				try:
					do_stuff(objKey)

					print "shit worked"
					break
				except (somerror) as e:
					if attempt < (max_retries - 1):
						logger.error('attempt %s for %s failed with %s, %s remaining', attempt + 1, objKey,e,max_retries - attempt)
						continue
					else:
						logger.error('All %s attempts for %s failed, aborting this file',max_retries,objKey)
						break