Delete item in a list using a for-loop

Question

I have an array with subjects and every subject has connected time. I want to compare every subjects in the list. If there are two of the same subjects, I want to add the ti

Answer 1

The best practice is to make a new list of the entries to delete, and to delete them after walking the list:

to_del = []
subjectlength = 8
for x in range(subjectlength):
    for y in range(x):
        if subject[x] == subject[y]:
            #add
            time[x] = time[x] + time[y]
            to_del.append(y)

to_del.reverse()
for d in to_del:
    del subject[d]
    del time[d]