Python Programming Question

[kylehotchkiss]

Hey!

I am learning python slowly but surely and was wondering how you would execute another program (like handbrake) in the background of a computer (so that the python application does not wait for handbrake to finish, and then you can check on the status of handbrake running whenever. Is that possible?

[nvteighen]

That sounds to multithreading... it's a really hard topic, as far as I heard (I never did it either...).

[PythonPower]

I've never used multithreading in Python, but in C it's easy.

The relevent doc page for Python appears to be:

http://docs.python.org/3.0/library/m...multithreading

[jimi_hendrix]

That sounds to multithreading... it's a really hard topic, as far as I heard (I never did it either...).

depends on the language...

i advise reading this and using the os.system() method to call the other program

[imdano]

I think you want the subprocess module, and the subprocess.Popen class specifically. It lets you spawn a non-blocking child process and check its pid/return code (if it's finished running)/etc.

edit: See the documentation here: http://docs.python.org/library/subprocess.html

edit edit: In the simplest case, you would use it like this:

import subprocess
import time

pobj = subprocess.Popen("ls")
while pobj.poll() is None:
    print "ls is still running"
    time.sleep(3)
print "ls return code is %s" % pobj.poll() 

[kylehotchkiss]

Thanks, yeah that is what I was looking for, I have been playing with that a little, and yours seems to tell me what to do.

I think you want the subprocess module, and the subprocess.Popen class specifically. It lets you spawn a non-blocking child process and check its pid/return code (if it's finished running)/etc.

edit: See the documentation here: http://docs.python.org/library/subprocess.html

edit edit: In the simplest case, you would use it like this:

import subprocess
import time

pobj = subprocess.Popen("ls")
while pobj.poll() is None:
    print "ls is still running"
    time.sleep(3)
print "ls return code is %s" % pobj.poll()