It's not that simple. How are you passing argv to the bash script? What about how `subprocess.run` changes the error output to include Python exception spam? Plus, in most editors, you lose all the bash syntax highlighting in the bash program chunk. I haven't seen a lot of hybrid programs like this work well.

That's why it's just the first stage of an incremental rewrite.

argv is easy to pass, though.

It is that simple. You can pass arguments to `bash -c` with no problems(just don't forget a dummy $0). If you don't want exception spam, replace `check=True` with explicit exit. Here you go, it's 5 lines now.

    #!/usr/bin/env python3
    import sys
    import subprocess
    result = subprocess.run(["bash", "-c", """
    echo I am in bash, I have $# args, arg1 is "$1"
    set -x
    "$@"
    """, "dummy.sh"] + sys.argv[1:])
    sys.exit(result.returncode)

    subprocess.run(["bash", "-c", f"rsync {shlex.quote(filename)} somehost: | some-script"])

The bash syntax highlighting will disappear, correct, and that is a downside. But hey, you are supposed to be rewriting this in python, so it's just more motivation :)