def _read_data(self, dataset, format=None):
<EOL>if not format:<EOL><INDENT>format_class = formats.detect(dataset)<EOL><DEDENT>else:<EOL><INDENT>if format not in formats.AVAILABLE.keys():<EOL><INDENT>raise ValueError("<STR_LIT>".format(format))<EOL><DEDENT>format_class = formats.AVAILABLE[format]<EOL><DEDENT>return format_class(dataset).to_iterable()<EOL>
Reads a data file and returns and iterable that can be used as
        testing or training data.