In case you did not know: When monkey patching [time.sleep](http://docs.python.org/2/library/time.html#time.sleep) is replaced with [gevent.sleep](http://www.gevent.org/gevent.html#gevent.sleep), which means that time.sleep waits _at least_ *delta* seconds instead of waiting exactly *delta* seconds. While your code waits for _at least_ *delta* seconds gevent switches to a different greenlet, and will switch back at some point when the other greenlet(s) wait for IO.
Note: This has no real conquence for your code - but just nice to now.