Decode all string values to Unicode. Optionally use to_str=True to ensure
    strings are str types and not unicode on Python 2.

def decode_tuple(data, encoding=None, errors='strict', keep=False,
                 normalize=False, preserve_dict_class=False, to_str=False):
    '''
    Decode all string values to Unicode. Optionally use to_str=True to ensure
    strings are str types and not unicode on Python 2.
    '''
    return tuple(
        decode_list(data, encoding, errors, keep, normalize,
                    preserve_dict_class, True, to_str)
    )