从python3脚本中，如何将字符串传递到bash程序中？

Question

As an example, here's what I've tried:

#!/usr/bin/env python3

from subprocess import Popen

message = "Lo! I am up on an ox."
Popen('less', shell=True).communicate(input=message)

As the last line, I also tried:

Popen('less', stdin=message, shell=True)

I can do what I want with:

Popen('echo "%s" | less' % message, shell=True)

Is there a more pythonic way of doing it?

Thanks!

Answer 1

@hyades answer above is certainly correct, and depending on what exactly you want might be best, but the reason your second example didn't work is because the stdin value must be file-like (just like unix). The following also works for me.

with tempfile.TemporaryFile(mode="w") as f:
     f.write(message)
     f.seek(0)
     Popen("less", stdin=f) 

Answer 2

import subprocess
p = subprocess.Popen('less', shell=True, stdout = subprocess.PIPE, stdin = subprocess.PIPE)
p.stdin.write('hey!!!'.encode('utf-8'))
print(p.communicate())

You can set up a PIPE for communication with the process

Answer 3

It is enough to add stdin=subprocess.PIPE (to redirect child's stdin) as @hyades suggested and universal_newlines=True (to enable text mode) to your code in order to pass a string to the child process:

#!/usr/bin/env python
from subprocess import Popen, PIPE

message = "Lo! I am up on an ox."
Popen(['cat'], stdin=PIPE, 
      universal_newlines=True).communicate(input=message)

Don't use shell=True unless you have a reason.