import shlex,subprocess,os
cmd = "/Applications/LibreOffice.app/Contents/MacOS/swriter --headless --invisible --convert-to pdf:writer_pdf_Export --outdir ~/Downloads ~/Downloads/HS303.xlsx"
#This works
os.popen(cmd)
#This doesnot work
subprocess.call(shlex.split(cmd))
Subprocess calls are not working. This was done in Mac OSX. Any idea as to why this is happening ?
The problem
The problem is the ~/Downloads path. the ~ is expanded by the shell environment which wasn't enabled when you called subprocess.call. Below is a simplified demonstration of the problem:
>>> import shlex, subprocess, os, os.path
>>> cmd = "ls ~/Downloads"
>>> print os.popen(cmd).read()
ubuntu-11.04-desktop-i386.iso
ubuntu-11.04-server-i386.iso
>>> print subprocess.check_output(shlex.split(cmd))
ls: cannot access ~/Downloads: No such file or directory
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/subprocess.py", line 537, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '['ls', '~/Downloads']' returned non-zero exit status 2
The solutions
There are two solutions you could use, either expand the ~ in python using os.path.expanduser or call subprocess.call/subprocess.check_output with argument shell=True. I prefer to use check_output over call because it returns any output that might have been produced by the command. Either solution below should solve your problem.
import shlex, subprocess, os, os.path
cmd = 'ls ' + os.path.expanduser('~/Downloads')
print subprocess.check_output(shlex.split(cmd))
cmd = 'ls ~/Downloads'
print subprocess.check_output(cmd, shell=True)
