blocks|key|2605372|text|您可以在命令执行后将stdout/err写入文件。在下面的示例中，我使用了酸洗，所以我确信我将能够在没有任何特定解析的情况下读取，以区分stdout/err，并且在某个时刻，我可以dumo退出代码和命令本身。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2605373|import+subprocess
import+cPickle

command+=+'ls+-altrh'
outfile+=+'log.errout'
pipe+=+subprocess.Popen(command,+stdout+=+subprocess.PIPE,
++++++++++++++++++++++++stderr+=+subprocess.PIPE,+shell+=+True)
stdout,+stderr+=+pipe.communicate()

f+=+open(outfile,+'w')
cPickle.dump({'out':+stdout,+'err':+stderr},f)
f.close()|code-block|syntax|javascript|2605374|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You may write the stdout/err to a file after the command execution.
In the example below I use pickling so I am sure I will be able to read without any particular parsing to differentiate between the stdout/err and at some point I could dumo the exitcode and the command itself.

<pre><code>import subprocess
import cPickle

command = 'ls -altrh'
outfile = 'log.errout'
pipe = subprocess.Popen(command, stdout = subprocess.PIPE,
 stderr = subprocess.PIPE, shell = True)
stdout, stderr = pipe.communicate()

f = open(outfile, 'w')
cPickle.dump({'out': stdout, 'err': stderr},f)
f.close()
</code></pre>

blocks|key|2605410|text|如果您希望交错以获得与以交互方式运行进程的顺序大致相同的顺序，那么您需要执行shell所做的操作，轮询stdin/stdout并按照轮询的顺序写入。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2605411|下面的代码完成了您想要做的事情--在本例中，将stdout/stderr发送到一个记录器信息/错误流。|2605412|tsk+=+subprocess.Popen(args,stdout=subprocess.PIPE,stderr=subprocess.PIPE)

poll+=+select.poll()
poll.register(tsk.stdout,select.POLLIN+%7C+select.POLLHUP)
poll.register(tsk.stderr,select.POLLIN+%7C+select.POLLHUP)
pollc+=+2

events+=+poll.poll()
while+pollc+>+0+and+len(events)+>+0:
++for+event+in+events:
++++(rfd,event)+=+event
++++if+event+&+select.POLLIN:
++++++if+rfd+==+tsk.stdout.fileno():
++++++++line+=+tsk.stdout.readline()
++++++++if+len(line)+>+0:
++++++++++logger.info(line[:-1])
++++++if+rfd+==+tsk.stderr.fileno():
++++++++line+=+tsk.stderr.readline()
++++++++if+len(line)+>+0:
++++++++++logger.error(line[:-1])
++++if+event+&+select.POLLHUP:
++++++poll.unregister(rfd)
++++++pollc+=+pollc+-+1
++++if+pollc+>+0:+events+=+poll.poll()
tsk.wait()|code-block|syntax|javascript|2605413|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

If you want to interleave to get roughly the same order that you would if you ran the process interactively then you need to do what the shell does and poll stdin/stdout and write in the order that they poll.

Here's some code that does something along the lines of what you want - in this case sending the stdout/stderr to a logger info/error streams.

<pre><code>tsk = subprocess.Popen(args,stdout=subprocess.PIPE,stderr=subprocess.PIPE)

poll = select.poll()
poll.register(tsk.stdout,select.POLLIN | select.POLLHUP)
poll.register(tsk.stderr,select.POLLIN | select.POLLHUP)
pollc = 2

events = poll.poll()
while pollc &gt; 0 and len(events) &gt; 0:
 for event in events:
 (rfd,event) = event
 if event &amp; select.POLLIN:
 if rfd == tsk.stdout.fileno():
 line = tsk.stdout.readline()
 if len(line) &gt; 0:
 logger.info(line[:-1])
 if rfd == tsk.stderr.fileno():
 line = tsk.stderr.readline()
 if len(line) &gt; 0:
 logger.error(line[:-1])
 if event &amp; select.POLLHUP:
 poll.unregister(rfd)
 pollc = pollc - 1
 if pollc &gt; 0: events = poll.poll()
tsk.wait()
</code></pre>

blocks|key|1924202|text|我建议你编写自己的处理程序，就像这样(没有经过测试，我希望你明白这个想法)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1924203|class+my_buffer(object):
++++def+__init__(self,+fileobject,+prefix):
++++++++self._fileobject+=+fileobject
++++++++self.prefix+=+prefix
++++def+write(self,+text):
++++++++return+self._fileobject.write('%25s+%25s'+%25+(self.prefix,+text))
++++#+delegate+other+methods+to+fileobject+if+necessary

log_file+=+open('log.log',+'w')
my_out+=+my_buffer(log_file,+'OK:')
my_err+=+my_buffer(log_file,+'!!!ERROR:')
p+=+subprocess.Popen(command,+stdout=my_out,+stderr=my_err,+shell=True)|code-block|syntax|javascript|1924204|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I suggest you write your own handlers, something like (not tested, I hope you catch the idea):

<pre><code>class my_buffer(object):
 def __init__(self, fileobject, prefix):
 self._fileobject = fileobject
 self.prefix = prefix
 def write(self, text):
 return self._fileobject.write('%s %s' % (self.prefix, text))
 # delegate other methods to fileobject if necessary

log_file = open('log.log', 'w')
my_out = my_buffer(log_file, 'OK:')
my_err = my_buffer(log_file, '!!!ERROR:')
p = subprocess.Popen(command, stdout=my_out, stderr=my_err, shell=True)
</code></pre>

blocks|key|12554|text|tsk+=+subprocess.Popen(args,stdout=subprocess.PIPE,stderr=subprocess.STDOUT)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|12555|subprocess.STDOUT是一个特殊的标志，它告诉子进程将所有stderr输出路由到stdout，从而将两个流组合在一起。|unstyled|offset|length|style|CODE|12556|顺便说一句，select在windows中没有poll()。子进程只使用文件句柄编号，并不调用文件输出对象的write方法。|12557|要捕获输出，请执行以下操作：|12558|logfile+=+open(logfilename,+'w')

while+tsk.poll()+is+None:
++++line+=+tsk.stdout.readline()
++++logfile.write(line)|12559|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/2/library/subprocess.html#subprocess.STDOUT^0|0|0|H|0|H|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|Z|8|@$G|10|H|11|I|J]]|9|@$G|12|H|13|1|14]]|A|$]]|$1|K|3|L|5|F|7|15|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|16|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|17|8|@]|9|@]|A|$B|C]]|$1|Q|3|-4|5|F|7|18|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

<pre><code>tsk = subprocess.Popen(args,stdout=subprocess.PIPE,stderr=subprocess.STDOUT)
</code></pre>

<a href="http://docs.python.org/2/library/subprocess.html#subprocess.STDOUT"><code>subprocess.STDOUT</code></a> is a special flag that tells subprocess to route all stderr output to stdout, thus combining your two streams.

btw, select doesn't have a poll() in windows. subprocess only uses the file handle number, and doesn't call your file output object's write method.

to capture the output, do something like:

<pre><code>logfile = open(logfilename, 'w')

while tsk.poll() is None:
 line = tsk.stdout.readline()
 logfile.write(line)
</code></pre>

blocks|key|2605506|text|我发现自己最近不得不解决这个问题，而且花了一段时间才得到我认为在大多数情况下都能正常工作的东西，所以就是这样！(它还有一个很好的副作用，可以通过python日志记录器处理输出，我注意到这是Stackoverflow上的另一个常见问题)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2605507|代码如下：|2605508|import+sys
import+logging
import+subprocess
from+threading+import+Thread

logging.basicConfig(stream=sys.stdout,level=logging.INFO)
logging.addLevelName(logging.INFO%2B2,'STDERR')
logging.addLevelName(logging.INFO%2B1,'STDOUT')
logger+=+logging.getLogger('root')

pobj+=+subprocess.Popen(['python','-c','print+42;bargle'],+
++++stdout=subprocess.PIPE,+stderr=subprocess.PIPE)

def+logstream(stream,loggercb):
++++while+True:
++++++++out+=+stream.readline()
++++++++if+out:
++++++++++++loggercb(out.rstrip())+++++++
++++++++else:
++++++++++++break

stdout_thread+=+Thread(target=logstream,
++++args=(pobj.stdout,lambda+s:+logger.log(logging.INFO%2B1,s)))

stderr_thread+=+Thread(target=logstream,
++++args=(pobj.stderr,lambda+s:+logger.log(logging.INFO%2B2,s)))

stdout_thread.start()
stderr_thread.start()

while+stdout_thread.isAlive()+and+stderr_thread.isAlive():
+++++pass|code-block|syntax|javascript|2605509|下面是输出：|2605510|STDOUT:root:42
STDERR:root:Traceback+(most+recent+call+last):
STDERR:root:++File+"<string>",+line+1,+in+<module>
STDERR:root:NameError:+name+'bargle'+is+not+defined|2605511|您可以替换子进程调用来做任何您想做的事情，我只是选择使用一个我知道会打印到stdout和stderr的命令来运行python。密钥位是在单独的线程中读取stderr和stdout。否则，您可能会阻止读取一个，而在另一个上有准备读取的数据。|2605512|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I found myself having to tackle this problem recently, and it took a while to get something I felt worked correctly in most cases, so here it is! (It also has the nice side effect of processing the output via a python logger, which I've noticed is another common question here on Stackoverflow).

Here is the code:

<pre><code>import sys
import logging
import subprocess
from threading import Thread

logging.basicConfig(stream=sys.stdout,level=logging.INFO)
logging.addLevelName(logging.INFO+2,'STDERR')
logging.addLevelName(logging.INFO+1,'STDOUT')
logger = logging.getLogger('root')

pobj = subprocess.Popen(['python','-c','print 42;bargle'], 
 stdout=subprocess.PIPE, stderr=subprocess.PIPE)

def logstream(stream,loggercb):
 while True:
 out = stream.readline()
 if out:
 loggercb(out.rstrip()) 
 else:
 break

stdout_thread = Thread(target=logstream,
 args=(pobj.stdout,lambda s: logger.log(logging.INFO+1,s)))

stderr_thread = Thread(target=logstream,
 args=(pobj.stderr,lambda s: logger.log(logging.INFO+2,s)))

stdout_thread.start()
stderr_thread.start()

while stdout_thread.isAlive() and stderr_thread.isAlive():
 pass
</code></pre>

Here is the output:

<pre><code>STDOUT:root:42
STDERR:root:Traceback (most recent call last):
STDERR:root: File "&lt;string&gt;", line 1, in &lt;module&gt;
STDERR:root:NameError: name 'bargle' is not defined
</code></pre>

You can replace the subprocess call to do whatever you want, I just chose running python with a command that I knew would print to both stdout and stderr. The key bit is reading stderr and stdout each in a separate thread. Otherwise you may be blocking on reading one while there is data ready to be read on the other.

blocks|key|1924272|text|目前，如果子进程不是接受-u标志的Python脚本，则所有其他答案都不会处理子进程端的缓冲。参见"Q:+Why+not+just+use+a+pipe+(popen())?"+in+the+pexpect+documentation。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1924273|要为一些基于C标准的(FILE*)程序模拟-u标志，您可以尝试stdbuf。|1924274|如果你忽略这一点，那么你的输出将不会被正确地交错，并且可能看起来像这样：|1924275|stderr
stderr
...large+block+of+stdout+including+parts+that+are+printed+before+stderr...|code-block|syntax|javascript|1924276|您可以使用以下客户端程序进行尝试，请注意使用/不使用-u标志的差异(['stdbuf',+'-o',+'L',+'child_program']也会修复输出)：|1924277|#!/usr/bin/env+python
from+__future__+import+print_function
import+random
import+sys
import+time
from+datetime+import+datetime

def+tprint(msg,+file=sys.stdout):
++++time.sleep(.1*random.random())
++++print("%25s+%25s"+%25+(datetime.utcnow().strftime('%25S.%25f'),+msg),+file=file)

tprint("stdout1+before+stderr")
tprint("stdout2+before+stderr")
for+x+in+range(5):
++++tprint('stderr%25d'+%25+x,+file=sys.stderr)
tprint("stdout3+after+stderr")|1924278|在Linux上，您可以使用pty获得与子进程交互运行时相同的行为，例如，下面是修改后的@T.Rojan's+answer|1924279|import+logging,+os,+select,+subprocess,+sys,+pty

logging.basicConfig(level=logging.INFO)
logger+=+logging.getLogger(__name__)

master_fd,+slave_fd+=+pty.openpty()
p+=+subprocess.Popen(args,stdout=slave_fd,+stderr=subprocess.PIPE,+close_fds=True)
with+os.fdopen(master_fd)+as+stdout:
++++poll+=+select.poll()
++++poll.register(stdout,+select.POLLIN)
++++poll.register(p.stderr,select.POLLIN+%7C+select.POLLHUP)

++++def+cleanup(_done=[]):
++++++++if+_done:+return
++++++++_done.append(1)
++++++++poll.unregister(p.stderr)
++++++++p.stderr.close()
++++++++poll.unregister(stdout)
++++++++assert+p.poll()+is+not+None

++++read_write+=+{stdout.fileno():+(stdout.readline,+logger.info),
++++++++++++++++++p.stderr.fileno():+(p.stderr.readline,+logger.error)}
++++while+True:
++++++++events+=+poll.poll(40)+#+poll+with+a+small+timeout+to+avoid+both
+++++++++++++++++++++++++++++++#+blocking+forever+and+a+busy+loop
++++++++if+not+events+and+p.poll()+is+not+None:
++++++++++++#+no+IO+events+and+the+subprocess+exited
++++++++++++cleanup()
++++++++++++break

++++++++for+fd,+event+in+events:
++++++++++++if+event+&+select.POLLIN:+#+there+is+something+to+read
++++++++++++++++read,+write+=+read_write[fd]
++++++++++++++++line+=+read()
++++++++++++++++if+line:
++++++++++++++++++++write(line.rstrip())
++++++++++++elif+event+&+select.POLLHUP:+#+free+resources+if+stderr+hung+up
++++++++++++++++cleanup()
++++++++++++else:+#+something+unexpected+happened
++++++++++++++++assert+0
sys.exit(p.wait())+#+return+child's+exit+code|1924280|它假设stderr始终是无缓冲/有行缓冲的，并且stdout是以交互模式进行行缓冲的。仅读取整行。如果输出中有未终止的行，程序可能会阻塞。|1924281|entityMap|0|LINK|mutability|MUTABLE|url|https://pexpect.readthedocs.io/en/stable/FAQ.html#whynotpipe|1|http://www.gnu.org/software/coreutils/manual/html_node/stdbuf-invocation.html#stdbuf-invocation|2|http://docs.python.org/dev/library/pty.html#example|3|https://stackoverflow.com/a/6810231/4279^0|C|2|1C|1W|0|0|B|5|L|2|V|6|V|6|1|0|0|0|Q|2|Y|12|0|0|D|3|D|3|2|17|H|3|0|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@$9|1D|A|1E|B|C]]|D|@$9|1F|A|1G|1|1H]]|E|$]]|$1|F|3|G|5|6|7|1I|8|@$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]]|D|@$9|1P|A|1Q|1|1R]]|E|$]]|$1|H|3|I|5|6|7|1S|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|1T|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|6|7|1U|8|@$9|1V|A|1W|B|C]|$9|1X|A|1Y|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|L|7|1Z|8|@]|D|@]|E|$M|N]]|$1|S|3|T|5|6|7|20|8|@$9|21|A|22|B|C]]|D|@$9|23|A|24|1|25]|$9|26|A|27|1|28]]|E|$]]|$1|U|3|V|5|L|7|29|8|@]|D|@]|E|$M|N]]|$1|W|3|X|5|6|7|2A|8|@]|D|@]|E|$]]|$1|Y|3|-4|5|6|7|2B|8|@]|D|@]|E|$]]]|Z|$10|$5|11|12|13|E|$14|15]]|16|$5|11|12|13|E|$14|17]]|18|$5|11|12|13|E|$14|19]]|1A|$5|11|12|13|E|$14|1B]]]]

At the moment all other answers don't handle buffering on the child subprocess' side if the subprocess is not a Python script that accepts <code>-u</code> flag. See <a href="https://pexpect.readthedocs.io/en/stable/FAQ.html#whynotpipe" rel="nofollow noreferrer">"Q: Why not just use a pipe (popen())?" in the pexpect documentation</a>.

To simulate <code>-u</code> flag for some of C stdio-based (<code>FILE*</code>) programs you could try <a href="http://www.gnu.org/software/coreutils/manual/html_node/stdbuf-invocation.html#stdbuf-invocation" rel="nofollow noreferrer"><code>stdbuf</code></a>.

If you ignore this then your output won't be properly interleaved and might look like:

<pre><code>stderr
stderr
...large block of stdout including parts that are printed before stderr...
</code></pre>

You could try it with the following client program, notice the difference with/without <code>-u</code> flag (<code>['stdbuf', '-o', 'L', 'child_program']</code> also fixes the output):

<pre><code>#!/usr/bin/env python
from __future__ import print_function
import random
import sys
import time
from datetime import datetime

def tprint(msg, file=sys.stdout):
 time.sleep(.1*random.random())
 print("%s %s" % (datetime.utcnow().strftime('%S.%f'), msg), file=file)

tprint("stdout1 before stderr")
tprint("stdout2 before stderr")
for x in range(5):
 tprint('stderr%d' % x, file=sys.stderr)
tprint("stdout3 after stderr")
</code></pre>

On Linux you could use <a href="http://docs.python.org/dev/library/pty.html#example" rel="nofollow noreferrer"><code>pty</code></a> to get the same behavior as when the subprocess runs interactively e.g., here's a modified <a href="https://stackoverflow.com/a/6810231/4279">@T.Rojan's answer</a>:

<pre><code>import logging, os, select, subprocess, sys, pty

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

master_fd, slave_fd = pty.openpty()
p = subprocess.Popen(args,stdout=slave_fd, stderr=subprocess.PIPE, close_fds=True)
with os.fdopen(master_fd) as stdout:
 poll = select.poll()
 poll.register(stdout, select.POLLIN)
 poll.register(p.stderr,select.POLLIN | select.POLLHUP)

 def cleanup(_done=[]):
 if _done: return
 _done.append(1)
 poll.unregister(p.stderr)
 p.stderr.close()
 poll.unregister(stdout)
 assert p.poll() is not None

 read_write = {stdout.fileno(): (stdout.readline, logger.info),
 p.stderr.fileno(): (p.stderr.readline, logger.error)}
 while True:
 events = poll.poll(40) # poll with a small timeout to avoid both
 # blocking forever and a busy loop
 if not events and p.poll() is not None:
 # no IO events and the subprocess exited
 cleanup()
 break

 for fd, event in events:
 if event &amp; select.POLLIN: # there is something to read
 read, write = read_write[fd]
 line = read()
 if line:
 write(line.rstrip())
 elif event &amp; select.POLLHUP: # free resources if stderr hung up
 cleanup()
 else: # something unexpected happened
 assert 0
sys.exit(p.wait()) # return child's exit code
</code></pre>

It assumes that stderr is always unbuffered/line-buffered and stdout is line-buffered in an interactive mode. Only full lines are read. The program might block if there are non-terminated lines in the output.

I would like to direct a python script's subprocess' stdout and stdin into the same file. What I don't know is how to make the lines from the two sources distinguishable? (For example prefix the lines from stderr with an exclamation mark.)

In my particular case there is no need for live monitoring of the subprocess, the executing Python script can wait for the end of its execution.

Merging a Python script's subprocess' stdout and stderr while keeping them distinguishable

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我想将python脚本子进程的stdout和stdin定向到同一个文件中。我不知道的是如何区分这两个来源的代码行？(例如，在stderr中的行前加上感叹号。)在我的特殊情况下，不需要实时监控子进程，正在执行的Python脚本可以等待其执行结束。

问合并Python脚本子进程的stdout和stderr，同时保持它们的可区分性
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问合并Python脚本子进程的stdout和stderr，同时保持它们的可区分性EN