Comment by BiteCode_dev

Damn, 15 years of python and I learn you can use -m twice. I've never even tried, didn't occur to me it would be supported.

EDIT: it support other options as well, like -c. That deserves an alias:

    debug_module() {
        if python -c "import ipdb" &>/dev/null; then
            python -m ipdb -c c -m "$@"
        else
            python -m pdb -c c -m  "$@"
        fi
    }