下面是运行任意命令返回其标准输出数据的Python代码，或在非零退出码上引发异常:
proc = subprocess.Popen(
cmd,
stderr=subprocess.STDOUT, # Merge stdout and stderr
stdout=subprocess.PIPE,
shell=True)
communication用于等待进程退出:
stdoutdata, stderrdata = proc.communicate()
子进程模块不支持超时——杀死运行超过X秒的进程的能力——因此，通信可能需要很长时间才能运行。
在Windows和Linux上运行的Python程序中实现超时的最简单方法是什么?
当前回答
我添加了从jcollado线程到我的Python模块easyprocess的解决方案。
安装:
pip install easyprocess
例子:
from easyprocess import Proc
# shell is not supported!
stdout=Proc('ping localhost').call(timeout=1.5).stdout
print stdout
其他回答
我添加了从jcollado线程到我的Python模块easyprocess的解决方案。
安装:
pip install easyprocess
例子:
from easyprocess import Proc
# shell is not supported!
stdout=Proc('ping localhost').call(timeout=1.5).stdout
print stdout
只是想写些简单点的东西。
#!/usr/bin/python
from subprocess import Popen, PIPE
import datetime
import time
popen = Popen(["/bin/sleep", "10"]);
pid = popen.pid
sttime = time.time();
waittime = 3
print "Start time %s"%(sttime)
while True:
popen.poll();
time.sleep(1)
rcode = popen.returncode
now = time.time();
if [ rcode is None ] and [ now > (sttime + waittime) ] :
print "Killing it now"
popen.kill()
另一种选择是写入临时文件以防止标准输出阻塞，而不需要使用communication()轮询。在其他答案没有的地方，这个方法对我有用;比如在窗户上。
outFile = tempfile.SpooledTemporaryFile()
errFile = tempfile.SpooledTemporaryFile()
proc = subprocess.Popen(args, stderr=errFile, stdout=outFile, universal_newlines=False)
wait_remaining_sec = timeout
while proc.poll() is None and wait_remaining_sec > 0:
time.sleep(1)
wait_remaining_sec -= 1
if wait_remaining_sec <= 0:
killProc(proc.pid)
raise ProcessIncompleteError(proc, timeout)
# read temp streams from start
outFile.seek(0);
errFile.seek(0);
out = outFile.read()
err = errFile.read()
outFile.close()
errFile.close()
This solution kills the process tree in case of shell=True, passes parameters to the process (or not), has a timeout and gets the stdout, stderr and process output of the call back (it uses psutil for the kill_proc_tree). This was based on several solutions posted in SO including jcollado's. Posting in response to comments by Anson and jradice in jcollado's answer. Tested in Windows Srvr 2012 and Ubuntu 14.04. Please note that for Ubuntu you need to change the parent.children(...) call to parent.get_children(...).
def kill_proc_tree(pid, including_parent=True):
parent = psutil.Process(pid)
children = parent.children(recursive=True)
for child in children:
child.kill()
psutil.wait_procs(children, timeout=5)
if including_parent:
parent.kill()
parent.wait(5)
def run_with_timeout(cmd, current_dir, cmd_parms, timeout):
def target():
process = subprocess.Popen(cmd, cwd=current_dir, shell=True, stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
# wait for the process to terminate
if (cmd_parms == ""):
out, err = process.communicate()
else:
out, err = process.communicate(cmd_parms)
errcode = process.returncode
thread = Thread(target=target)
thread.start()
thread.join(timeout)
if thread.is_alive():
me = os.getpid()
kill_proc_tree(me, including_parent=False)
thread.join()
在Python 3.7.8中超时测试后捕获的输出示例:
try:
return subprocess.run(command, shell=True, capture_output=True, timeout=20, cwd=cwd, universal_newlines=True)
except subprocess.TimeoutExpired as e:
print(e.output.decode(encoding="utf-8", errors="ignore"))
assert False;
异常子进程。TimeoutExpired有输出和其他成员:
cmd -用于生成子进程的命令。 timeout -超时时间，单位为秒。 output -子进程的输出，如果它是由run()或 check_output()。否则,没有。 stdout -输出的别名，用于与stderr对称。 stderr -子进程的stderr输出，如果它被捕获 run()。否则,没有。
更多信息:https://docs.python.org/3/library/subprocess.html#subprocess.TimeoutExpired
