subprocess.Popen 和缓冲进程输出
从 python 代码内部，我想运行一个从标准输入获取参数的二进制程序。使用 subprocess 模块，这应该很简单：
import subprocess
command = [ 'my_program' ]
p = subprocess.Popen( command, \
stdin = subprocess.PIPE, stdout = subprocess.PIPE, \
env={ "GFORTRAN_UNBUFFERED_ALL": "1"} )
p.stdin.write ( stdin_stuff )
while True:
o = p.stdout.readline()
if p.poll() != None:
break
# Do something with stdout
现在，这会启动程序，但 python 脚本只是挂在那里。我知道这很可能是由于 gfortran （我用来编译 my_program 正在缓冲其 stdout 流。gfortran 允许使用 GFORTRAN_UNBUFFERED_ALL 环境变量，就像我所做的那样，以及在 fortran 代码中使用 FLUSH() 内在函数，但仍然没有运气：python 代码仍然挂起。
From inside python code, I want to run a binary program that gets its parameters from stdin. Using the subprocess module, this should be straightforward:
import subprocess
command = [ 'my_program' ]
p = subprocess.Popen( command, \
stdin = subprocess.PIPE, stdout = subprocess.PIPE, \
env={ "GFORTRAN_UNBUFFERED_ALL": "1"} )
p.stdin.write ( stdin_stuff )
while True:
o = p.stdout.readline()
if p.poll() != None:
break
# Do something with stdout
Now, this launches the program, but the python script just hangs there. I understand that this may well be due gfortran (which I use to compile my_program is buffering its stdout stream. gfortran allows one to use the GFORTRAN_UNBUFFERED_ALL environmental variable, as I have done, as well as using the FLUSH() intrinsic in the fortran code, but still no luck: the python code still hangs.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
使用
Popen.communicate()将字符串发送到进程的stdin，而不是手动写入。You should have better luck using
Popen.communicate()to send strings to the process'stdinrather than manually writing to it.为了补充 Aphex 的答案，这里是 < a href="http://docs.python.org/library/subprocess.html" rel="nofollow noreferrer">文档：
To complement Aphex's answer, here the relevant part of the documentation: