I have a python script that spawns a few subprocesses but never more than n at a time. I want to write a shell script to confirm that it has no more than n subprocesses at any given time, but also generally has n processes running. If I have the pid of the python program inside a shell script, how do I check the number of subprocesses that that pid currently has? E.g.

python script.py &
pid=$!
while true
do
    # do something that prints number of subprocesses of
    # the process $pid to stdout
    sleep 1
done

I have a Python script that spawns a few subprocesses but never more than n at a time. 

I want to write a shell script to confirm that it has no more than n subprocesses at any given time, but also that generally it has n processes running. 

If I have the PID of the Python program inside a shell script, how do I check the number of subprocesses that that PID currently has? E.g.

python script.py &
pid=$!
while true
do
    # do something that prints number of subprocesses of
    # the process $pid to stdout
    sleep 1
done

I have a python script that spawns a few subprocesses but never more than n at a time. I want to write a shell script to confirm that it has no more than n subprocesses at any given time, but also generally has n processes running. If I have the pid of the python program inside a shell script, how do I check the number of subprocesses that that pid currently has? E.g.

python script.py &
pid=$!
while true;
    # do something that prints number of subprocesses of
    # the process $pid to stdout
    sleep 1

I have a python script that spawns a few subprocesses but never more than n at a time. I want to write a shell script to confirm that it has no more than n subprocesses at any given time, but also generally has n processes running. If I have the pid of the python program inside a shell script, how do I check the number of subprocesses that that pid currently has? E.g.

python script.py &
pid=$!
while true
do
    # do something that prints number of subprocesses of
    # the process $pid to stdout
    sleep 1
done