Why use python at all? You might forget to remove it and check it into a repository. Just run your python command with && and another command to run to do the alerting.
python myscript.py && notify-send 'Alert' 'Your task is complete' && paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga python myscript.py && notify-send 'Alert' 'Your task is complete' && paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga or drop a function into your .bashrc. I use apython here but you could override 'python'
function apython() { /usr/bin/python $* notify-send 'Alert' "python $* is complete" paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga } function apython() { /usr/bin/python $* notify-send 'Alert' "python $* is complete" paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga }