python管道只有标准输入，输出一次，怎么办两次或更多次 [英] python pipe only stdin,out once, how to do twice or more time

问题描述

成功的python管道标准输入，仅此源一次

success python pipe stdin, out only one time this source

main.py

import subprocess from subprocess import PIPE, STDOUT

player_pipe = subprocess.Popen(["source\call.py", 'arg1'], stdin=PIPE,
     stdout=PIPE, stderr=STDOUT, shell=True)

player_pipe.stdin.write("Send Msg\n")
get_stdout = player_pipe.stdout.readline()
print("[Get Msg]" + get_stdout)

player_pipe.kill()
player_pipe.wait()

call.py

import sys

getMsg = raw_input()
print getMsg

但是我想要两次或更多次标准输入时间

but I want twice or more time stdin, out

因此请更新源，但不起作用

so update source but it's not work

此来源出了什么问题

main.py(更新无效)

main.py (update-not work)

import subprocess from subprocess import PIPE, STDOUT

player_pipe = subprocess.Popen(["source\call.py", 'arg1'], stdin=PIPE,
     stdout=PIPE, stderr=STDOUT, shell=True)

player_pipe.stdin.write("Send Msg\n")
get_stdout = player_pipe.stdout.readline()
print("[Get Msg]" + get_stdout)

player_pipe.stdin.write("Send Msg2\n")
get_stdout = player_pipe.stdout.readline()
print("[Get Msg]" + get_stdout)

player_pipe.kill()
player_pipe.wait()

call.py(更新无效)

call.py(update-not work)

import sys

getMsg = raw_input()
print getMsg

getMsg2 = raw_input()
print getMsg2

:D

推荐答案

call.py的输出已缓冲.因此您必须flush()将其发送到main.py.

the output of call.py is buffered. so you have to flush() it to send to main.py.

#!/usr/bin/python2
import sys

getMsg = raw_input()
print getMsg
sys.stdout.flush()

getMsg2 = raw_input()
print getMsg2
sys.stdout.flush()

请注意，至少当您的操作系统是Linux时，您需要shebang #!/usr/bin/python2(我不知道为什么OP的代码在没有shebang的情况下才能工作.也许有些Windows魔术?).

Note that you need shebang #!/usr/bin/python2 at least when your OS is Linux (I don't know why OP's code works without shebang. Maybe some Windows magic ?).

还可以使用-u选项不缓冲python的输出.

Also you can use -u option not to buffer the output of python.

player_pipe = subprocess.Popen(["/usr/bin/python2","-u","./call.py"], stdin=PIPE,
     stdout=PIPE, stderr=STDOUT, shell=False)

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