How to use the jellyfish.compat._zip_longest function in jellyfish

if abs(len1-len2) >= 3:
        return None

    # get minimum rating based on sums of codexes
    lensum = len1 + len2
    if lensum <= 4:
        min_rating = 5
    elif lensum <= 7:
        min_rating = 4
    elif lensum <= 11:
        min_rating = 3
    else:
        min_rating = 2

    # strip off common prefixes
    for c1, c2 in _zip_longest(codex1, codex2):
        if c1 != c2:
            if c1:
                res1.append(c1)
            if c2:
                res2.append(c2)

    unmatched_count1 = unmatched_count2 = 0
    for c1, c2 in _zip_longest(reversed(res1), reversed(res2)):
        if c1 != c2:
            if c1:
                unmatched_count1 += 1
            if c2:
                unmatched_count2 += 1

    return (6 - max(unmatched_count1, unmatched_count2)) >= min_rating

min_rating = 4
    elif lensum <= 11:
        min_rating = 3
    else:
        min_rating = 2

    # strip off common prefixes
    for c1, c2 in _zip_longest(codex1, codex2):
        if c1 != c2:
            if c1:
                res1.append(c1)
            if c2:
                res2.append(c2)

    unmatched_count1 = unmatched_count2 = 0
    for c1, c2 in _zip_longest(reversed(res1), reversed(res2)):
        if c1 != c2:
            if c1:
                unmatched_count1 += 1
            if c2:
                unmatched_count2 += 1

    return (6 - max(unmatched_count1, unmatched_count2)) >= min_rating