Returns the executable.

def _get_args_for_reloading():
    """Returns the executable."""
    rv = [sys.executable]
    main_module = sys.modules["__main__"]
    mod_spec = getattr(main_module, "__spec__", None)
    if mod_spec:
        # Parent exe was launched as a module rather than a script
        rv.extend(["-m", mod_spec.name])
        if len(sys.argv) > 1:
            rv.extend(sys.argv[1:])
    else:
        rv.extend(sys.argv)
    return rv