Using python subprocess to call sox

Question

I am trying to use subprocess.call to run a sox command as follows:

import subprocess
subprocess.call(['sox','-n','-b','16','output.wav','synth','2.25','sine','300','vol','0.5'])

While this command works fine on a unix command line, here I get the following error:

OSError: [Errno 2] No such file or directory 

I also tried this using os.system:

os.system('sox -n -b 16 output.wav synth 2.25 sine 300 vol 0.5')

And I get a command not found error. Calling other unix commands works fine for me, e.g.

subprocess.call(['say' ,'hello'])

Any ideas? I'm running OS 10.8.4, python 2.7.6, sox 14.4.1.

Answer 1

Try using cmdstring = "sox -n -b 16 relative_path/output.wav synth 2.25 sine 300 vol 0.5"

Then calling os.system(cmdstring)