example-code-2e/attic/concurrency/spinner_asyncio2.py
2015-04-17 21:29:30 -03:00

47 lines
1.1 KiB
Python

# spinner_asyncio2.py
# credits: Example by Luciano Ramalho inspired by
# Michele Simionato's multiprocessing example
# source:
# http://python-3-patterns-idioms-test.readthedocs.org/en/latest/CoroutinesAndConcurrency.html
import sys
import asyncio
DELAY = 0.1
DISPLAY = '|/-\\'
@asyncio.coroutine
def spinner_func(before='', after=''):
write, flush = sys.stdout.write, sys.stdout.flush
while True:
for char in DISPLAY:
msg = '{} {} {}'.format(before, char, after)
write(msg)
flush()
write('\x08' * len(msg))
try:
yield from asyncio.sleep(DELAY)
except asyncio.CancelledError:
return
@asyncio.coroutine
def long_computation(delay):
# emulate a long computation
yield from asyncio.sleep(delay)
@asyncio.coroutine
def supervisor(delay):
spinner = loop.create_task(spinner_func('Please wait...', 'thinking!'))
yield from long_computation(delay)
spinner.cancel()
if __name__ == '__main__':
loop = asyncio.get_event_loop()
loop.run_until_complete(supervisor(3))
loop.close()