Question

Say I need to do the following in python:

import os
os.system("a.out 1 \n 3 \n 2 \n 5 \n 2...")

Here I have separate string to store the parameters:

par="1 \n 3 \n 2 \n 5 \n 2..."

Not sure how to pipe it to “a.out” in python. Thanks!

Answer 1

Assuming you want to pass that string to stdin,

import subprocess

p = subprocess.Popen(['a.out'], stdin=subprocess.PIPE)
p.communicate('1 \n 3 \n 2 \n 5 \n 2...\n')

Edit: since you want to read from a file, that’s actually even easier.

import subprocess
subprocess.call(['a.out'], stdin=file('a.inp'))