Subprocess with a Python Session?

[Calvin Spealman]

No matter what I do I cant get the following code to do what I expect.
I hadn't used subprocess t o read and write to pipes of a
still-running app, and I just can't seem to get it right. What gives?

import subprocess

p = subprocess.Popen("python", stdout=subprocess.PIPE, stdin=subprocess.PIPE)
p.stdin.write('print 10\n')
assert p.stdout.readline() == '10\n'

 

[Nick Craig-Wood]

No matter what I do I cant get the following code to do what I expect.
I hadn't used subprocess t o read and write to pipes of a
still-running app, and I just can't seem to get it right. What gives?

import subprocess

p = subprocess.Popen("python", stdout=subprocess.PIPE, stdin=subprocess.PIPE)
p.stdin.write('print 10\n')
assert p.stdout.readline() == '10\n'

To read and write to a still running app, you'll want to use pexpect
probably.

http://pexpect.sourceforge.net/

Note that running python under pexpect puts it into interactive
mode.