I need to compare two lists (list1 and list2) on sign changes and I want to invert those indices in the second list that undergo sign changes. This means that I want to change the -4 and the -11 in list2 to 4 and 11. How can I do this?
list1 = [1,4,5,6,8,10]
list2 = [3,10,-4,7,-11,10]
>Solution :
If I understand your question correctly, then you can do this fairly straightforward with list comprehension:
list3 = [j*-1 if (i < 0 and j > 0) or (i > 0 and j < 0) else j for i, j in zip(list1, list2)]
print(list3)
[3, 10, 4, 7, 11, 10]