Convert [(section0, nts0), (section1, nts1), ... to [*nts0, *nts1, ...

def get_sections_flattened(section_nts):
        """Convert [(section0, nts0), (section1, nts1), ... to [*nts0, *nts1, ..."""
        nt_flds = list(section_nts[0][1][0]._fields)
        # Flatten section_nts 2-D list
        if 'section' in nt_flds:
            return [nt for _, nts in section_nts for nt in nts]
        # Flatten section_nts 2-D list, and add sections to each namedtuple
        nt_flds.append('section')
        nts_flat = []
        ntobj = cx.namedtuple("Nt", " ".join(nt_flds))
        for section_name, nts in section_nts:
            for nt_go in nts:
                vals = list(nt_go) + [section_name]
                nts_flat.append(ntobj._make(vals))
        return nts_flat