Python 使用模块&x27；子流程'；超时

下面是运行任意命令返回其

stdout

数据的Python代码，或者在非零退出代码上引发异常：

proc = subprocess.Popen(
    cmd,
    stderr=subprocess.STDOUT,  # Merge stdout and stderr
    stdout=subprocess.PIPE,
    shell=True)

通信

用于等待进程退出：

stdoutdata, stderrdata = proc.communicate()

子进程

模块不支持超时—能够终止运行时间超过X秒的进程—因此，

通信

可能需要永远运行

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？

如果您在Unix上

import signal
  ...
class Alarm(Exception):
    pass

def alarm_handler(signum, frame):
    raise Alarm

signal.signal(signal.SIGALRM, alarm_handler)
signal.alarm(5*60)  # 5 minutes
try:
    stdoutdata, stderrdata = proc.communicate()
    signal.alarm(0)  # reset the alarm
except Alarm:
    print "Oops, taking too long!"
    # whatever else

---

我已经在Windows、Linux和Mac上成功地使用了。如果您使用的是Cygwin Python，您将需要，否则本机Windows进程将不会被终止。

以下是Alex Martelli的解决方案，它是一个具有适当进程终止功能的模块。其他方法不起作用，因为它们不使用proc.communicate（）。因此，如果您有一个产生大量输出的进程，它将填充其输出缓冲区，然后阻塞，直到您从中读取某些内容

from os import kill
from signal import alarm, signal, SIGALRM, SIGKILL
from subprocess import PIPE, Popen

def run(args, cwd = None, shell = False, kill_tree = True, timeout = -1, env = None):
    '''
    Run a command with a timeout after which it will be forcibly
    killed.
    '''
    class Alarm(Exception):
        pass
    def alarm_handler(signum, frame):
        raise Alarm
    p = Popen(args, shell = shell, cwd = cwd, stdout = PIPE, stderr = PIPE, env = env)
    if timeout != -1:
        signal(SIGALRM, alarm_handler)
        alarm(timeout)
    try:
        stdout, stderr = p.communicate()
        if timeout != -1:
            alarm(0)
    except Alarm:
        pids = [p.pid]
        if kill_tree:
            pids.extend(get_process_children(p.pid))
        for pid in pids:
            # process might have died before getting to this line
            # so wrap to avoid OSError: no such process
            try: 
                kill(pid, SIGKILL)
            except OSError:
                pass
        return -9, '', ''
    return p.returncode, stdout, stderr

def get_process_children(pid):
    p = Popen('ps --no-headers -o pid --ppid %d' % pid, shell = True,
              stdout = PIPE, stderr = PIPE)
    stdout, stderr = p.communicate()
    return [int(p) for p in stdout.split()]

if __name__ == '__main__':
    print run('find /', shell = True, timeout = 3)
    print run('find', shell = True)

---

另一个选项是写入临时文件以防止stdout阻塞，而不需要使用communicate（）轮询。这对我来说是可行的，而其他答案则不然；例如在windows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()

outFile=tempfile.SpooledTemporaryFile（）
errFile=tempfile.SpooledTemporaryFile（）
proc=subprocess.Popen（args，stderr=errFile，stdout=outFile，universal\u newlines=False）
等待\u剩余\u秒=超时
当proc.poll（）为“无”并等待\u秒>0时：
时间。睡眠（1）
等待\u剩余\u秒-=1
如果等待秒我不太了解底层细节；但是，考虑到这一点
python 2.6 API提供了等待线程和
终止进程，在单独的环境中运行进程如何
线

我的计算机中此代码段的输出为：

Thread started
Process started
Process finished
Thread finished
0
Thread started
Process started
Terminating process
Thread finished
-15

可以看出，在第一次执行中
已正确完成（返回代码0），而第二个中的
进程已终止（返回代码-15）

我没有在windows上测试过；但是，除了更新示例之外
命令，我想应该能用，因为我在
记录任何表示thread.join或process.terminate
不受支持。
我已经实现了我可以从其中一些中收集到的功能。这可以在Windows中使用，因为这是一个社区wiki，我想我也可以共享我的代码：

class Command(threading.Thread):
    def __init__(self, cmd, outFile, errFile, timeout):
        threading.Thread.__init__(self)
        self.cmd = cmd
        self.process = None
        self.outFile = outFile
        self.errFile = errFile
        self.timed_out = False
        self.timeout = timeout

    def run(self):
        self.process = subprocess.Popen(self.cmd, stdout = self.outFile, \
            stderr = self.errFile)

        while (self.process.poll() is None and self.timeout > 0):
            time.sleep(1)
            self.timeout -= 1

        if not self.timeout > 0:
            self.process.terminate()
            self.timed_out = True
        else:
            self.timed_out = False

然后从另一个类或文件：

        outFile =  tempfile.SpooledTemporaryFile()
        errFile =   tempfile.SpooledTemporaryFile()

        executor = command.Command(c, outFile, errFile, timeout)
        executor.daemon = True
        executor.start()

        executor.join()
        if executor.timed_out:
            out = 'timed out'
        else:
            outFile.seek(0)
            errFile.seek(0)
            out = outFile.read()
            err = errFile.read()

        outFile.close()
        errFile.close()

我将带线程的解决方案从
jcollado
添加到我的Python模块中

安装：

pip install easyprocess

例如：

from easyprocess import Proc

# shell is not supported!
stdout=Proc('ping localhost').call(timeout=1.5).stdout
print stdout

虽然我没有详细研究过它，但我在ActiveState中发现它似乎对这类事情非常有用。除了subprocess.Popen（…，close_fds=True）

，至少我已经准备好用Python编写shell脚本了。

我使用的解决方案是在shell命令前面加上前缀。如果comand花费的时间太长，timelimit将停止它，并且Popen将由timelimit设置返回代码。如果大于128，则表示timelimit终止了进程

---

另请参见

jcollado的答案可以使用类进行简化：

---

一旦您了解了*unix中运行的全过程机器，您将很容易找到更简单的解决方案：

考虑这个简单的例子，如何使用select.select（）使timeoutable communicate（）方法（现在在*nix上也几乎所有地方都可用）。这也可以用epoll/poll/kqueue编写，但是select.select（）变量可能是一个很好的例子。select.select（）的主要限制（速度和1024最大fds）不适用于您的任务

它在*nix下工作，不创建线程，不使用信号，可以从任何线程启动（不仅仅是主线程），并且速度足够快，可以从我的机器上的标准输出读取250mb/s的数据（i5 2.3ghz）

在通信结束时加入stdout/stderr时出现问题。如果你有巨大的程序输出，这可能会导致大内存使用。但是可以使用较小的超时多次调用communicate（）

class Popen(subprocess.Popen):
    def communicate(self, input=None, timeout=None):
        if timeout is None:
            return subprocess.Popen.communicate(self, input)

        if self.stdin:
            # Flush stdio buffer, this might block if user
            # has been writing to .stdin in an uncontrolled
            # fashion.
            self.stdin.flush()
            if not input:
                self.stdin.close()

        read_set, write_set = [], []
        stdout = stderr = None

        if self.stdin and input:
            write_set.append(self.stdin)
        if self.stdout:
            read_set.append(self.stdout)
            stdout = []
        if self.stderr:
            read_set.append(self.stderr)
            stderr = []

        input_offset = 0
        deadline = time.time() + timeout

        while read_set or write_set:
            try:
                rlist, wlist, xlist = select.select(read_set, write_set, [], max(0, deadline - time.time()))
            except select.error as ex:
                if ex.args[0] == errno.EINTR:
                    continue
                raise

            if not (rlist or wlist):
                # Just break if timeout
                # Since we do not close stdout/stderr/stdin, we can call
                # communicate() several times reading data by smaller pieces.
                break

            if self.stdin in wlist:
                chunk = input[input_offset:input_offset + subprocess._PIPE_BUF]
                try:
                    bytes_written = os.write(self.stdin.fileno(), chunk)
                except OSError as ex:
                    if ex.errno == errno.EPIPE:
                        self.stdin.close()
                        write_set.remove(self.stdin)
                    else:
                        raise
                else:
                    input_offset += bytes_written
                    if input_offset >= len(input):
                        self.stdin.close()
                        write_set.remove(self.stdin)

            # Read stdout / stderr by 1024 bytes
            for fn, tgt in (
                (self.stdout, stdout),
                (self.stderr, stderr),
            ):
                if fn in rlist:
                    data = os.read(fn.fileno(), 1024)
                    if data == '':
                        fn.close()
                        read_set.remove(fn)
                    tgt.append(data)

        if stdout is not None:
            stdout = ''.join(stdout)
        if stderr is not None:
            stderr = ''.join(stderr)

        return (stdout, stderr)

---

我修改了苏苏迪奥的答案。现在函数返回：（

returncode

，

stdout

，

stderr

，

timeout

）-

stdout

，

stderr

被解码为utf-8字符串

def kill_proc(proc, timeout):
  timeout["value"] = True
  proc.kill()

def run(cmd, timeout_sec):
  proc = subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  timeout = {"value": False}
  timer = Timer(timeout_sec, kill_proc, [proc, timeout])
  timer.start()
  stdout, stderr = proc.communicate()
  timer.cancel()
  return proc.returncode, stdout.decode("utf-8"), stderr.decode("utf-8"), timeout["value"]

---

不幸的是，我的雇主对源代码的披露有非常严格的规定，所以我不能提供实际的代码。但就我的口味而言，最好的解决方案是创建一个子类，重写

Popen.wait（）

以轮询而不是无限期等待，并创建

Popen.\uuuu init\uuu

以接受超时参数。完成此操作后，所有其他

Popen

方法（调用

wait

）将按预期工作，包括Python 3.3+中的

communicate

：

from subprocess import STDOUT, check_output

output = check_output(cmd, stderr=STDOUT, timeout=seconds)

output

是一个字节字符串，包含命令的合并stdout、stderr数据

在问题文本中指定的非零退出状态下引发

CalledProcessError

，而不是

proc.communicate（）

方法

我删除了

shell=True

，因为它经常被不必要地使用。如果

cmd

确实需要它，您可以随时将其添加回去。如果添加

shell=True

，即如果子进程生成自己的子进程

check_output（）

返回的时间可能比超时指示的时间晚得多，请参阅

---

Python2.x上的超时功能可以通过3.2+子流程模块的后端口使用。

只是想写一些更简单的东西

#!/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()

---

这是我的解决方案，我使用了线程和事件：

import subprocess
from threading import Thread, Event

def kill_on_timeout(done, timeout, proc):
    if not done.wait(timeout):
        proc.kill()

def exec_command(command, timeout):

    done = Event()
    proc = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    watcher = Thread(target=kill_on_timeout, args=(done, timeout, proc))
    watcher.daemon = True
    watcher.start()

    data, stderr = proc.communicate()
    done.set()

    return data, stderr, proc.returncode

在行动中：

In [2]: exec_command(['sleep', '10'], 5)
Out[2]: ('', '', -9)

In [3]: exec_command(['sleep', '10'], 11)
Out[3]: ('', '', 0)

通过子流程模块中的

call（）

和

communicate（）

（从Python3.3开始）：

这将调用该命令并引发异常

subprocess.TimeoutExpired

如果命令在20秒后没有完成

然后，您可以处理异常以继续您的代码，例如：

try:
    subprocess.call("command", timeout=20, shell=True)
except subprocess.TimeoutExpired:
    # insert code here

---

希望这有帮助。

没有人提到使用

超时import subprocess

subprocess.call("command", timeout=20, shell=True)

subprocess.TimeoutExpired

try:
    subprocess.call("command", timeout=20, shell=True)
except subprocess.TimeoutExpired:
    # insert code here

pipe  = subprocess.Popen('...')

timeout =  10

results = pipe.waitOrTerminate(timeout)

import subprocess32

try:
    output = subprocess32.check_output(command, shell=True, timeout=3)
except subprocess32.TimeoutExpired as e:
    print e

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()

from logging import error
from subprocess import Popen
from threading import Event
from threading import Thread


class ExpirablePopen(Popen):

    def __init__(self, *args, **kwargs):
        self.timeout = kwargs.pop('timeout', 0)
        self.timer = None
        self.done = Event()

        Popen.__init__(self, *args, **kwargs)

    def __tkill(self):
        timeout = self.timeout
        if not self.done.wait(timeout):
            error('Terminating process {} by timeout of {} secs.'.format(self.pid, timeout))
            self.kill()

    def expirable(func):
        def wrapper(self, *args, **kwargs):
            # zero timeout means call of parent method
            if self.timeout == 0:
                return func(self, *args, **kwargs)

            # if timer is None, need to start it
            if self.timer is None:
                self.timer = thr = Thread(target=self.__tkill)
                thr.daemon = True
                thr.start()

            result = func(self, *args, **kwargs)
            self.done.set()

            return result
        return wrapper

    wait = expirable(Popen.wait)
    communicate = expirable(Popen.communicate)


if __name__ == '__main__':
    from subprocess import PIPE

    print ExpirablePopen('ssh -T git@bitbucket.org', stdout=PIPE, timeout=1).communicate()

import subprocess
from datetime import datetime
from select import select

def call_with_timeout(cmd, timeout):
    started = datetime.now()
    sp = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    while True:
        p = select([sp.stdout], [], [], timeout)
        if p[0]:
            p[0][0].read()
        ret = sp.poll()
        if ret is not None:
            return ret
        if (datetime.now()-started).total_seconds() > timeout:
            sp.kill()
            return None

import os
import sys
import signal
import subprocess
from multiprocessing import Pool

cores_for_parallelization = 4
timeout_time = 15  # seconds

def main():
    jobs = [...YOUR_JOB_LIST...]
    with Pool(cores_for_parallelization) as p:
        p.map(run_parallel_jobs, jobs)

def run_parallel_jobs(args):
    # Define the arguments including the paths
    initial_terminal_command = 'C:\\Python34\\python.exe'  # Python executable
    function_to_start = 'C:\\temp\\xyz.py'  # The multithreading script
    final_list = [initial_terminal_command, function_to_start]
    final_list.extend(args)

    # Start the subprocess and determine the process PID
    subp = subprocess.Popen(final_list)  # starts the process
    pid = subp.pid

    # Wait until the return code returns from the function by considering the timeout. 
    # If not, terminate the process.
    try:
        returncode = subp.wait(timeout=timeout_time)  # should be zero if accomplished
    except subprocess.TimeoutExpired:
        # Distinguish between Linux and Windows and terminate the process if 
        # the timeout has been expired
        if sys.platform == 'linux2':
            os.kill(pid, signal.SIGTERM)
        elif sys.platform == 'win32':
            subp.terminate()

if __name__ == '__main__':
    main()

cmd = "timeout 20 "+ cmd
subprocess.Popen(cmd.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(output, err) = p.communicate()

Run the command described by args. Wait for command to complete, then return a CompletedProcess instance.

 from gevent.subprocess import Popen, PIPE, STDOUT

 def call_sys(cmd, timeout):
      p= Popen(cmd, shell=True, stdout=PIPE)
      output, _ = p.communicate(timeout=timeout)
      assert p.returncode == 0, p. returncode
      return output

 call_sys('./t.sh', 2)

 # t.sh example
 sleep 5
 echo done
 exit 1

import time
import subprocess

def run_command(cmd, timeout=0):
    start_time = time.time()
    df = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    while timeout and df.poll() == None:
        if time.time()-start_time >= timeout:
            df.kill()
            return -1, ""
    output = '\n'.join(df.communicate()).strip()
    return df.returncode, output

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;

import subprocess

timeout = 25 # seconds
cmd = f"timeout --preserve-status --foreground {timeout} ping duckgo.com"
exit_c, out = subprocess.getstatusoutput(cmd)

if (exit_c == 0):
    print("success")
else:
    print("Error: ", out)