Events are objects that are used for communication between threads. A thread waits for a signal while another thread outputs it. Basically, an event object manages an internal flag that can be set to true with the set() method and reset to false with the clear() method. The wait() method blocks until the flag is true.
To understand the thread synchronization through the event object, let's take a look again at the producer/consumer problem:
import time
from threading import Thread, Event
import random
items = []
event = Event()
class consumer(Thread):
def __init__(self, items, event):
Thread.__init__(self)
self.items = items
self.event = event
def run(self):
while True:
time.sleep(2)
self.event.wait()
item = self.items.pop()
print ('Consumer notify : %d popped from list by %s'\
%(item, self.name))
class producer(Thread...