## vim: filetype=makopython

def _coerce_bytes(label, value, what='a bytes string', or_none=False):
    """
    Take bytes (forwarded as-is to C) but also accept text (encoded using
    the system encoding).
    """
    if value is None and or_none:
        return None
    elif isinstance(value, bytes):
        return value
    elif isinstance(value, str):
        return value.encode()
    else:
        raise TypeError('`{}` argument must be {} (got {})'
                        .format(label, what, _type_fullname(type(value))))