# code16.py

import threading

import time

import queue

class Producer(threading.Thread):

def __init__(self, que):

super().__init__()

self.que = que

def run(self):

with open('raw_numbers.txt') as file:

for line in file:

values = tuple([int(l) for l in line.strip().split(',')])

self.que.put(values)

print('[PRODUCER] The queue has {} elements.'.format( \

self.que.qsize()))

# Simulates a slower process

time.sleep(0.001)

def consumer(que):

with open('processed_numbers.txt', 'w') as file:

while True:

# A try/except clause is used in order to stop

# the consumer once there is no elements left in the

# queue. If not for this, the consumer would be executing

# for ever

try:

# If no elements are left in the queue, an Empty

# exception is raised

numbers = que.get(False)

except queue.Empty:

break

else:

file.write('{}\n'.format(sum(numbers)))

que.task_done()

# qsize() returns the queue size

print('[CONSUMER] The queue now has {} elements.'.format( \

que.qsize()))

# Simulates a complex process. If the consumer was faster

# than the producer, the threads would end abruptly

time.sleep(0.005)

if __name__ == '__main__':

q = queue.Queue()

# a producer is created and executed

p = Producer(q)

p.start()

# a consumer thread is created and executed with the same queue

c = threading.Thread(target=consumer, args=(q,))

c.start()