Run multiple python scripts concurrently with different CMD name

Question

I try to call a.py and b.py concurrently in test.py by multiprocessing.Process(), it worked. But the process CMD name of a.py, b.py and test.py, which are '/usr/bin/python /tmp/test.py', are the same .

# ps -ef | grep b.py
UID   PID  PPID   C STIME   TTY           TIME CMD
501 61486 39878   0  2:33PM ??         0:00.05 /usr/bin/python /tmp/test.py
501 61487 61486   0  2:33PM ??         0:00.01 /usr/bin/python /tmp/test.py
501 61488 61486   0  2:33PM ??         0:00.01 /usr/bin/python /tmp/test.py

I'd like to have these three processes show different CMD names by 'ps -ef' as below: (which can help me to identify whether different process is running or not.)

# ps -ef | grep b.py
UID   PID  PPID   C STIME   TTY           TIME CMD
501 61486 39878   0  2:33PM ??         0:00.05 /usr/bin/python /tmp/test.py
501 61487 61486   0  2:33PM ??         0:00.01 /usr/bin/python /tmp/a.py
501 61488 61486   0  2:33PM ??         0:00.01 /usr/bin/python /tmp/b.py

Please help advice:)

Source code is as below:

test.py:

import multiprocessing
import a
import b


p1 = multiprocessing.Process(target=a.printa)
p2 = multiprocessing.Process(target=b.printb)

p1.start()
p2.start()

a.py:

import time


def printa():
    while True:
        print 'a'
        time.sleep(1)

if __name__ == '__main__':
    printa()

b.py:

import time

def printb():
    while True:
        print 'b'
        time.sleep(1)

if __name__ == '__main__':
    printb()

This is a solution to my question, but it seems a little bit odd by listing lines of **python xxx.py &**. http://stackoverflow.com/questions/28549641/run-multiple-python-scripts-concurrently — zzxwill, Apr 12 '17 at 07:11
@stovfl Can `subprocess` call a specific method of a module? Thanks. — zzxwill, Apr 14 '17 at 11:01
Yes, simplest case call the`method` beneath of `if __name__ ` — stovfl, Apr 14 '17 at 12:22
Could you please help explain a little bit more about the solution? Like an example? Thanks:) — zzxwill, Apr 17 '17 at 10:12

silgon · Answer 1 · 2017-04-12T08:45:29.983

You are using a.py and b.py as a library in python, therefore it is called under the same name as the executed file test.py. Either using multiprocessingor joblib the same situation occurs.

There is a name option in the Process method (multiprocessing.Process(self, group=None, target=None, name=None, args=(), kwargs={})), but as @fedterzi says, it is only for identification purposes.

If you want to call a process or file, you can use the library subprocess.

Depending on the task you are performing, such as parellelizing a bunch of processes, you could also use gnu parallel or some other method through bash in order to accomplish your desired behavior.

No, the name of the process won't change the process title, it's just there for identification purposes — fedterzi, Apr 12 '17 at 07:56

score 0 · Answer 2 · answered Apr 17 '17 at 13:11

0

Read Python » 2.7.13 Documentation using-the-subprocess-module
Choose from subprocess a NOWAIT Method, edit your Questions code accordingly.

import subprocess

def openCmd(name):
    return subprocess.?

if __name__ == '__main__':
    while True:
        key = raw_input('input 1=open, 0=terminate, q=quit:')
        print(key)
        if key == '1':
            A_p = openCmd(('a'))
            B_p = openCmd(('b'))
        if key == '0':
            A_p.terminate()
            B_p.terminate()
        if key == 'q':
            break

Tested with Python:2.7.9

answered Apr 17 '17 at 13:11

stovfl

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What does 'return subprocess.?' mean? Thanks:) – zzxwill May 05 '17 at 08:37
@WillZhou: `subprocess.?` is a placeholder. Read the suggested Documentation and choose a Method from the `subprocess` module. – stovfl May 05 '17 at 08:45

Run multiple python scripts concurrently with different CMD name

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