How to redirect python script cmd output to a file?

Question

So I have a python script that outputs text to the console and I need that logged to a file instead, but the script is quite complex and I don't code python, so I would rather not alter it.

I want to do this

>python script.py arg1 arg2 ... argn > "somefile.txt"

But it won't work, and my guess is that python takes > and "somefile.txt" as arguments..

Can this be achieved and how?

• immortal: Your guess is wrong. In what way doesn't it work? What do you see?
• Garin GG: I see the output in the console, and there is no file created.
• cfeduke: Are you certain its not outputting to STDERR?
• Eryk Sun: Did you add the CMD tag because you're running Python from the Windows CMD shell? In that case, if python script.py ... > somefile.txt 2>&1 doesn't work, then the script is writing directly to the console instead of stdout or stderr.
• Clock Slave: Possible duplicate of How to execute a python script and write output to txt file?

Answer 1

$ (python script.py one two) > test.txt

Or if you want to see the output and also write it to a file:

$ python script.py one two | tee test.txt

If this still isn't writing to the file, try redirecting STDERR:

$ python script.py one two 2>&1 | tee test.txt

• Garin GG: Tried the one with the brackets and the file gets created but the output isn't redirected and the file remains empty. Sorry but I don't understand your syntax for the rest.. By '$' do you imply linux bash? Because I'm talking about windows command prompt
• Garin GG: Yeah, got "'tee' is not recognized as an internal or external command..."
• Eryk Sun: @GarinGG, Windows isn't distributed with a tee command. You can install one, but you didn't ask about that anyway. Just redirect stdout via >somefile.txt and redirect stderr to stdout (i.e. the same file) via 2>&1.
• cfeduke: Yeah sorry, used to writing my bash examples starting with a $ and didn't even think about Windows. If you are using Cygwin it may include tee (dunno, its been years).

Answer 2

Add these lines of code to the beginning of the python file.

import sys
sys.stdout = open('somefile.txt', 'w')

This is setting the sys.stdout to a file object of your choice.

Answer 3

Since the script is not yours, my guess is that it uses python logging module. If this is the case then you just need to reconfigure the logging module to use stdout. See https://stackoverflow.com/a/28194953/292787 for how to do it.

import logging
import sys
logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)

Answer 4

Use:

python script.py arg1 arg2 ... argn >> somefile.txt