def slice_indexer(self, start=None, end=None, step=None, kind=None):
        start_slice, end_slice = self.slice_locs(start, end, step=step,
                                                 kind=kind)

        # return a slice
        if not lib.isscalar(start_slice):
            raise AssertionError("Start slice bound is non-scalar")
        if not lib.isscalar(end_slice):
            raise AssertionError("End slice bound is non-scalar")

        return slice(start_slice, end_slice, step)
Map True to 'true'
dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py/Index.slice_indexer--crossover with--dataset/ETHPy150Open plivo/plivohelper-python/plivohelper.py/Element.bool2txt