Run two programs at the same time

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Run two programs at the same time

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#1 by (2 votes)
#2 by (1 votes)

2

Let's imagine that I have two scripts written in a python.

The first is called programa_1.py and the second programa_2.py .

To be executed, and because it opens some particular files, the programa_1.py needs to run in a directory named, say:

C:\Users\test_1

To be executed, and because it opens other particular files, the programa_2.py needs to run in a directory named, say:

C:\Users\test_2

Program_1 generates a file called datos_1.csv

Program_2 generates a file called datos_2.csv

My question:

Can I create a new script that executes both programs at the same time?

python python-3.x

asked by pyring 28.11.2017 в 17:00

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2 answers

1

If you want to use threading in python 3 you should make these small modifications from execfile to exec open like the example

import threading

def ejecutar_doc1():
    exec(open("C:\Users\test_1.py").read())
def ejecutar_doc2():
    exec(open("C:\Users\test_2.py").read())

hilo1 = threading.Thread(target=ejecutar_doc1)
hilo2 = threading.Thread(target=ejecutar_doc2)
hilo1.start()
hilo2.start()

answered by 28.11.2017 в 17:13

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score 2 · Accepted Answer

If you want them to run completely parallel (the threads are limited in CPython by the GIL) you need to create a process for each script.

In the case of two independent scripts you can create a third script and use subprocess.Popen to create a process for each script:

#!/usr/bin/env python 

import subprocess


# Iterable con las rutas de los scripts
scripts_paths = ("C:/Users/test_1/script1.py", "C:/Users/test_2/script2.py")

# Creamos cada proceso    
procesos = [subprocess.Popen(["python", script]) for script in scripts_paths]

# Esperamos a que todos los subprocesos terminen.
for proceso in procesos:
    proceso.wait()

# Resto de código a ejecutar cuando terminen todos los subprocesos.

If you need or want to check if the processes finished or not correctly you can use a list by compression that contains the exit codes returned by wait :

exit_codes = [p.wait() for p in p1, p2]

Usually 0 is returned if the program ended successfully, so you can condition the subsequent behavior based on it:

#!/usr/bin/env python 

import subprocess


scripts_paths = ("C:/Users/test_1/script1.py", "C:/Users/test_2/script2.py")

ps = [subprocess.Popen(["python", script]) for script in scripts_paths]
exit_codes = [p.wait() for p in ps]

if not any(exit_codes):
    print("Todos los procesos terminaroin con éxito")
else:
    print("Algunos procesos terminaron de forma inesperada.")

If the scripts require arguments, they can also be passed without problems.

If you need both processes to interact with each other securely you should use multiprocessing and establish secure mechanisms for communication between them.