How to skip error message pop-up with subprocess in Python

Question

I am using subprocess in Python to call an external program on WINDOWS. I control the process with ThreadPool so that I can limit it to max 6 processes at the same time, and new process continuously began when one was done.

Codes as below:

### some codes above

### Code of Subprocess Part

from multiprocessing.pool import ThreadPool as Pool

def FAST_worker(file):
    p = subprocess.Popen([r'E:/pyworkspace/FAST/FAST_RV_W64.exe', file],
                         cwd = r'E:/pyworkspace/FAST/',
                         shell = True)
    p.wait()

# List of *.in filenames
FAST_in_pathname_li = [
    '334.in',
    '893.in',
    '9527.in',
    ...
    '114514.in',
    '1919810.in',
]

# Limit max 6 processes at same time
with Pool(processes = 6) as pool:
    for result in pool.imap_unordered(FAST_worker, FAST_in_pathname_li):
        pass

### some codes below

I got problem when the external program unexpectedly terminated and showed error message pop-up. Though the other 5 processes still kept going, the whole progress will finally get stuck at the "subprocess part" and couldn't go forward anymore. (unless I came to my desk and manually clicked "Shut down the program")

What I want to know is how can I avoid the pop-up and make the whole script process keep going, like bypass the error message or something, rather than manual click, in order to avoid wasting time.

Grégoire Roussel · Accepted Answer · 2019-09-16T12:46:52.657

Since we don't know enough about the program FAST_worker is calling, I'll assume you already checked there isn't any "kill on error" or "quiet" mode that would be more convenient to use in a script.

My two cents: maybe you can setup a timeout on the worker execution, so that a stuck process is killed automatically after a certain delay.

Building on the snippet provided here, here is a draft:

from threading import Timer

def FAST_worker(file, timeout_sec):
    def kill_proc():
        """called by the Timer thread upon expiration"""
        p.kill()
        # maybe add task to list of failed task, for tracability

    p = subprocess.Popen([r'E:/pyworkspace/FAST/FAST_RV_W64.exe', file],
                         cwd = r'E:/pyworkspace/FAST/',
                         shell = True)
    # setup timer to kill the process after a timeout
    timer = Timer(timeout_sec, kill_proc)
    try:
        timer.start()
        stdout, stderr = p.wait()
    finally:
        timer.cancel()

Note that there are also GUI automation libraries in python that can do the clicking for you, but that is likely to be more tedious to program:

I've tried applying code above into my script, but the behavior of the process became weird. (sorry for not know how to explain) Maybe I'll contact with the writer of the `FAST_RV_W64.exe` program. Still thanks for your help. — Chunpin, Sep 17 '19 at 08:09

How to skip error message pop-up with subprocess in Python

1 Answers1