@rama @Kaliiixx You'll love this one: a queer behavior I spotted in Python 3:

./script works perfectly: every time something is printed, it's shown on stdout

But ./script > file.log won't write immediately, it will buffer the output.

No more output? You ctrl + C the script to end it? Bye the output … (to mitigate that: a TERM signal, the one you got with kill <pid>, will nicely quits the Python script after a flush)

Now imagine this script. It's intended to follow notifications as a LIVE stream. But if you want a log and do ./script | tee file.log, you lost the live feature.

So we need to explicitly flush the stdout, to be able to use that with tee the way any user would expect it to work: sys.stdout.flush().

See also https://www.turnkeylinux.org/blog/unix-buffering