[warvariuc]

Or

    #!/bin/sh
    """:"
    # bash code here; finds a suitable python interpreter and execs this file.
    for pyver in 3.6 3.7 3.8 3.9; do
        which python$pyver > /dev/null 2>&1 && exec python$pyver "$0" "$@"
    done
    echo "No appropriate python interpreter found." >&2
    exit 1
    ":"""

[ByThyGrace]

Is it still bash code if you're running /bin/sh?

[tempodox]

Not for shellcheck(1). It warns about bashisms if it sees `/bin/sh` after the hash-bang.

[mrlemke]

Presumably not, it depends on your system. Some people symlink sh to bash.

[gnubison]

Which(1) doesn’t necessarily return a non-zero exit code if it can’t find a program. Instead, the portable alternative for scripts is command -v.

[dagw]

That approach will break now that python 3.10 is out

[mattnewton]

Or, it won't break your code if you haven't tested in 3.10 yet ;)

[cozzyd]

don't you want to go in descending order?