How to hide output of subprocess in Python 2.7

Question

I'm using eSpeak on Ubuntu and have a Python 2.7 script that prints and speaks a message:

import subprocess
text = 'Hello World.'
print text
subprocess.call(['espeak', text])

eSpeak produces the desired sounds, but clutters the shell with some errors (ALSA lib..., no socket connect) so i cannot easily read what was printed earlier. Exit code is 0.

Unfortunately there is no documented option to turn off its verbosity, so I'm looking for a way to only visually silence it and keep the open shell clean for further interaction.

How can I do this?

Answer 1

Redirect the output to DEVNULL:

import os
import subprocess

FNULL = open(os.devnull, 'w')
retcode = subprocess.call(['echo', 'foo'], 
    stdout=FNULL, 
    stderr=subprocess.STDOUT)

It is effectively the same as running this shell command:

retcode = os.system("echo 'foo' &> /dev/null")

Update: This answer applies to the original question relating to python 2.7. As of python >= 3.3 an official subprocess.DEVNULL symbol was added.

retcode = subprocess.call(['echo', 'foo'], 
    stdout=subprocess.DEVNULL, 
    stderr=subprocess.STDOUT)