<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _kwa(val, onts, mdb_safe=False):
 """ Key word argument conversion :param val: A dictionary :param onts: dictionary with schemas to use in the conversion schema namespase is the key in the dictionary :return: A converted dictionary """

    if not mdb_safe:
        return dict([(k, from_dict(v, onts)) for k, v in val.items()
                     if k not in EXP_SKIP])
    else:
        _skip = ["_id"]
        _skip.extend(EXP_SKIP)
        return dict([(k.replace("__", "."), from_dict(v, onts)) for k, v in
                     val.items() if k not in _skip])