def get(self, slug, cf=None, **kwargs):
        """Handler for getting a DataFrame.

        :param cf: should be in this pattern ``days|2014-05-01|2014-05-29``
        """
        if not cf:
            cf_to = datetime.date.today() - datetime.timedelta(1)
            cf_from = datetime.timedelta(30) - cf_to
        else:
            _, cf_from, cf_to = cf.split('|')
            cf_to = datetime.datetime.strptime(cf_to, "%Y-%m-%d").date() - \
                datetime.timedelta(1)

        func = getattr(self, "get_{}".format(slug))
        return func(cf_from=cf_from, cf_to=cf_to, **kwargs)
dataset/ETHPy150Open eleme/polaris/polaris/ext/time_series.py/TimeSeries.get/swapped operands of `-`