Retrieve files generated by PureCN_Dx

def _get_purecn_dx_files(paired, out):
    """Retrieve files generated by PureCN_Dx
    """
    out_base = "%s-dx" % utils.splitext_plus(out["rds"])[0]
    all_files = []
    for key, ext in [[("mutation_burden",), "_mutation_burden.csv"],
                     [("plot", "signatures"), "_signatures.pdf"],
                     [("signatures",), "_signatures.csv"]]:
        cur_file = "%s%s" % (out_base, ext)
        out = tz.update_in(out, key, lambda x: cur_file)
        all_files.append(os.path.basename(cur_file))
    return out_base, out, all_files