def METHOD_NAME(lines, separator):
    max_name_len = 0
    for line in lines:
        name, stats = line.rsplit('\t', 1)
        max_name_len = max(max_name_len, len(name))
    for line in lines:
        name, stats = line.rsplit('\t', 1)
        yield name.ljust(max_name_len) + separator + stats