example-code-2e/17-futures/demo_executor_map.py
2015-04-15 04:48:25 -03:00

35 lines
820 B
Python

"""
Experiment with ``ThreadPoolExecutor.map``
"""
# BEGIN EXECUTOR_MAP
from time import sleep, strftime
from concurrent import futures
def display(*args): # <1>
print(strftime('[%H:%M:%S]'), end=' ')
print(*args)
def loiter(n): # <2>
msg = '{}loiter({}): doing nothing for {}s...'
display(msg.format('\t'*n, n, n))
sleep(n)
msg = '{}loiter({}): done.'
display(msg.format('\t'*n, n))
return n * 10 # <3>
def main():
display('Script starting.')
executor = futures.ThreadPoolExecutor(max_workers=3) # <4>
results = executor.map(loiter, range(5)) # <5>
display('results:', results) # <6>.
display('Waiting for individual results:')
for i, result in enumerate(results): # <7>
display('result {}: {}'.format(i, result))
main()
# END EXECUTOR_MAP