How Can I Capture Output And Show It At The Same Time With Python?

I have a pretty long running job, which runs for several minutes and then gets restarted. The task outputs various information which I capture like this: output = subprocess.Popen(

Solution 1:

You can try something like this :

cmd = ["./my_program.sh"]
p = subprocess.Popen( cmd, shell=False, stdout=subprocess.PIPE)   # launch the processwhile p.poll() isNone:          # check if the process is still alive
    out = p.stdout.readline()    # if it is still alive, grab the output
    do_something_with(out)       # do what you want with it

Solution 2:

You could read it one line at a time:

from subprocess import Popen, PIPE

p = Popen('grep -ir graph .', stdout=PIPE)
whilenot p.returncode:
    s = p.stdout.readline()
    print s
    p.poll()

In this way, you are only blocking for the time it takes to process to output a single line.

Solution 3:

You can use the "tee" command. It does exactly what you need from it. http://www.computerhope.com/unix/utee.htm