how can understand line?
o = [[[-1 in range(int(o[0][1]))] k in range(int(i[0]))] in o]
how transform comprehension list basic loops?
your list comprehension 3 loops in one. translate this:
o = [] in o: o1 = [] k in range(int(i[0])): o2 = [] j in range(int(i[0][1])): o2.append(-1) o1.append(o2) o.append(o1) 