Getting decode error.

[snippsat]

Can test function.

# cm.py
import subprocess

def run_process(cmd_args):
    with subprocess.Popen(cmd_args, stdout=subprocess.PIPE, stderr=subprocess.PIPE) as p:
        out, err = p.communicate()
    return out

E:\div_code\new
λ ptpython -i cm.py
>>> res = run_process('ls')

# Return bytes
>>> res
b'001.png\n002.png\n003.png\n004.png\ncm.py\n'

# To string
>>> res.decode()
'001.png\n002.png\n003.png\n004.png\ncm.py\n'

# Write to file
>>> with open('output.txt', 'w') as f:
...     f.write(f'Process Output: \n{res.decode()}\n')

output.txt:

Output:
Process Output: 
001.png
002.png
003.png
004.png
cm.py

If return out, err then it will be a tuple.

>>> res
(b'001.png\n002.png\n003.png\n004.png\ncm.py\noutput.txt\n', b'')

>>> res[0]
b'001.png\n002.png\n003.png\n004.png\ncm.py\noutput.txt\n'

>>> res[0].decode()
'001.png\n002.png\n003.png\n004.png\ncm.py\noutput.txt\n'

# Or unpack back
>>> out, err = res

>>> out
b'001.png\n002.png\n003.png\n004.png\ncm.py\noutput.txt\n'