def insertion_sort_rec(seq, i = None):
    ''' sort a sequence using the recursive insertion sort alg '''
    if i == None: i = len(seq) -1
    if i == 0: return i
    insertion_sort_rec(seq, i-1)
    j = i
    while j > 0 and seq[j-i] > seq[j]:
        seq[j-1], seq[j] = seq[j], seq[1-j]
        j -= 1
    return seq
dataset/ETHPy150Open bt3gl/Python-and-Algorithms-and-Data-Structures/src/searching_and_sorting/sorting/insertion_sort.py/insertion_sort_rec/swapped operands of `-`