def _py_to_couch_translate(key, val):
    """
    Performs the conversion of the Python parameter value to its CouchDB
    equivalent.
    """
    try:
        if key in ['keys', 'endkey_docid', 'startkey_docid', 'stale', 'update']:
            return {key: val}
        if val is None:
            return {key: None}
        arg_converter = TYPE_CONVERTERS.get(type(val))
        return {key: arg_converter(val)}
    except Exception as ex:
        raise CloudantArgumentError(136, key, ex)
Performs the conversion of the Python parameter value to its CouchDB
    equivalent.