你不需要线程来并行运行子流程:
from subprocess import Popen
commands = [
'date; ls -l; sleep 1; date',
'date; sleep 5; date',
'date; df -h; sleep 3; date',
'date; hostname; sleep 2; date',
'date; uname -a; date',
]
# run in parallel
processes = [Popen(cmd, shell=True) for cmd in commands]
# do other things here..
# wait for completion
for p in processes: p.wait()
为了限制并发命令的数量,可以使用multiprocessing.dummy.Pool
线程并提供与multiprocessing.Pool
使用进程相同的接口:
from functools import partial
from multiprocessing.dummy import Pool
from subprocess import call
pool = Pool(2) # two concurrent commands at a time
for i, returncode in enumerate(pool.imap(partial(call, shell=True), commands)):
if returncode != 0:
print("%d command Failed: %d" % (i, returncode))
该答案演示了限制并发子进程数的各种技术:它显示了multiprocessing.Pool,concurrent.futures
,线程+基于队列的解决方案。
你可以限制并发子进程的数量,而无需使用线程/进程池:
from subprocess import Popen
from itertools import islice
max_workers = 2 # no more than 2 concurrent processes
processes = (Popen(cmd, shell=True) for cmd in commands)
running_processes = list(islice(processes, max_workers)) # start new processes
while running_processes:
for i, process in enumerate(running_processes):
if process.poll() is not None: # the process has finished
running_processes[i] = next(processes, None) # start new process
if running_processes[i] is None: # no new processes
del running_processes[i]
break