__all__ = ["rev_comp", "barcode_comb"] def rev_comp(seq): rc_dict = { "A": "T", "T": "A", "C": "G", "G": "C", "a": "t", "t": "a", "c": "g", "g": "c", "U": "A", "u": "a", } rc_seq = "" for x in seq[::-1]: try: rc_seq = rc_seq + rc_dict[x] except KeyError: rc_seq = rc_seq + x # print(rc_seq) return rc_seq def barcode_comb(seq): if len(seq) % 2 == 1: raise ValueError("The sequence length should be an even number.") l = len(seq) // 2 f1 = seq[:l] f2 = seq[l:] r1 = rev_comp(f1) r2 = rev_comp(f2) print(f"""F1F2\t{f1}{f2} R1R2\t{r1}{r2} F1R2\t{f1}{r2} R1F2\t{r1}{f2} F2F1\t{f2}{f1} R2R1\t{r2}{r1} F2R1\t{f2}{r1} R2F1\t{r2}{f1}""")