We want the same multiple callback support, but now we'd like to implement it so that the callbacks are managed through an external class called EventBinder.
Implement the EventBinder class.
from threading import Thread
import time
class EventBinder(object):
"""Implement the methods for this class"""
class Downloader(object):
def __init__(self, url_list):
self.url_list = url_list
self.done = EventBinder()
def start_downloads(self):
thread = Thread(target=self.download_all)
thread.start()
def download_all(self):
count = 0
start_time = time.time()
for url in self.url_list:
print 'Downloading', url
time.sleep(0.3)
count += 1
end_time = time.time()
self.done.fire(count, end_time-start_time)
if __name__ == '__main__':
url_list = xrange(1, 10)
downloader = Downloader(url_list)
@downloader.done
def _(count, time_elapsed):
print "Fetched", count, "files in", time_elapsed, "seconds"
@downloader.done
def _(count, time_elapsed):
print '%s downloaded in %0.3f minutes' % (count, time_elapsed / 60.0)
downloader.start_downloads()
print 'Waiting for the result...'
Expected result:
Waiting for the result... Downloading 1 Downloading 2 Downloading 3 Downloading 4 Downloading 5 Downloading 6 Downloading 7 Downloading 8 Downloading 9 Fetched 9 files in 2.71900010109 seconds 9 downloaded in 0.045 minutes
Solution: downloader3.py
Hints: