setting STDOUT and/or STDERR

[Gribouillis]

is this code good enough or is there a more expected (and pythonic) way to do this?

I think it is ok if you want to do this very specific thing, redirect every output of subprocesses to the file.

I would probably choose another way. First you can redirect the streams when the script is invoked, for example let the script be

# myscript.py
import subprocess as sp
import sys

# print our args
print(sys.argv)
sys.stdout.flush()

# run some command which creates output
sp.run(["date"])

It can be invoked at the console with a redirection

Output:
λ python paillasse/pf/myscript.py --spam eggs ham >/tmp/bigscript.log 2>&1 
λ 

Let us check the content of /tmp/bigscript.log

Output:
λ cat /tmp/bigscript.log
['paillasse/pf/myscript.py', '--spam', 'eggs', 'ham']
mar. 05 déc. 2023 11:09:13 CET
λ 

If we don't want to redirect it at the console, we can interpose a driver script which does the redirection

# driver.py
from pathlib import Path
import subprocess as sp
import sys

myscript = Path(__file__).parent / "myscript.py"

with Path("/tmp/bigscript.log").open("w") as ofile:
    sp.run([sys.executable, myscript, *sys.argv[1:]], stdout=ofile, stderr=sp.STDOUT)

Let us invoke the driver

Output:
λ python paillasse/pf/driver.py --spam eggs ham
λ 

We now check the content of the output file

Output:
λ cat /tmp/bigscript.log
['/home/eric/Projets/Scratch/2023-01/paillasse/pf/myscript.py', '--spam', 'eggs', 'ham']
mar. 05 déc. 2023 11:11:43 CET
λ