Python script outputs to console even when it's' run in the background

Question

I am running a python script in background, but why does it still prints to console, even when piped to a file?

I tried the following command:

python script.py &
python script.py > output.txt &

I tried with a simple script:

print "hello world"

With

python script.py &

It still prints to console.

But

python script.py > output.txt &

works as intended and does not print to console.

Answer 1

Probably it is outputing on stderr. Try this:

python script.py > output.txt 2>&1 &

Alternatively it looks like you might have started a background task that is still running:

python script.py &

Type fg to bring it to the foreground, and then kill it with Ctrl-C.