def _register_function(func, con):
    """Register a Python callable with a SQLite connection `con`.

    Parameters
    ----------
    func : callable
    con : sqlalchemy.Connection
    """
    nargs = number_of_arguments(func)
    con.connection.connection.create_function(func.__name__, nargs, func)
Register a Python callable with a SQLite connection `con`.

    Parameters
    ----------
    func : callable
    con : sqlalchemy.Connection