Asyncio prints the execution status of a coroutine
I have a bunch of coroutines that do some work
@asyncio.coroutine
def do_work():
global COUNTER
result = ...
if result.status == 'OK':
COUNTER += 1
and one more
COUNTER = 0
@asyncio.coroutine
def display_status():
while True:
print(COUNTER)
yield from asyncio.sleep(1)
which should display how many coroutines have finished their work. How do you accomplish this task correctly? The following solution doesn't work
@asyncio.coroutine
def spawn_jobs():
coros = []
for i in range(10):
coros.append(asyncio.Task(do_work()))
yield from asyncio.gather(*coros)
if __name__ == '__main__':
loop = asyncio.get_event_loop()
loop.create_task(display_status())
loop.run_until_complete(spawn_jobs())
loop.close()
I expect the counter to be printed to the console every second no matter what the do_work () coroutines do. But I have only two outputs: 0 and after a few seconds I repeat 10.
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But I only have two outputs: 0 and after a few seconds it repeats 10.
I cannot reproduce it. If I use:
import asyncio
import random
@asyncio.coroutine
def do_work():
global COUNTER
yield from asyncio.sleep(random.randint(1, 5))
COUNTER += 1
I am getting output like this:
0
0
4
6
8
Task was destroyed but it is pending!
task: <Task pending coro=<display_status() running at most_wanted.py:16> wait_for=<Future pending cb=[Task._wakeup()] created at ../Lib/asyncio/tasks.py:490> created at most_wanted.py:27>
Endless loop in display_status()
raises a warning at the end. To avoid warning; exit the loop when all tasks in the package have been completed:
#!/usr/bin/env python3
import asyncio
import random
from contextlib import closing
from itertools import cycle
class Batch:
def __init__(self, n):
self.total = n
self.done = 0
async def run(self):
await asyncio.wait([batch.do_work() for _ in range(batch.total)])
def running(self):
return self.done < self.total
async def do_work(self):
await asyncio.sleep(random.randint(1, 5)) # do some work here
self.done += 1
async def display_status(self):
while self.running():
await asyncio.sleep(1)
print('\rdone:', self.done)
async def display_spinner(self, char=cycle('/|\-')):
while self.running():
print('\r' + next(char), flush=True, end='')
await asyncio.sleep(.3)
with closing(asyncio.get_event_loop()) as loop:
batch = Batch(10)
loop.run_until_complete(asyncio.wait([
batch.run(), batch.display_status(), batch.display_spinner()]))
Output
done: 0
done: 2
done: 3
done: 4
done: 10
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Solution using a module threading
SHOW_STATUS = True
def display_status_sync():
while SHOW_STATUS:
print(S_REQ)
time.sleep(1)
if __name__ == '__main__':
new_thread = threading.Thread(target=display_status_sync)
new_thread.start()
loop.run_until_complete(spawn_jobs())
SHOW_STATS = False
new_thread.join()
loop.close()
But I want to achieve similar functionality using asyncio coroutines. Is it possible to do this?
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