'shlex' me ha salvado a menudo de estos errores. import subprocess import shlex cmd = shlex.split('''convert -depth 8 -size{}x{} RGB:- /tmp/random.png'''.format(size, size)) result = subprocess.run(cmd, stdin=result.stdout, stdout=subprocess.PIPE) -- Jordi Funollet Pujol http://www.linkedin.com/in/jordifunollet