replacing items in nested lists python

Question

I am trying to make a duplicate list of lists and change one element to another within the nested lists of the duplicate list but am having some trouble. How I made the dup

Answer 1

order_1 = []
for item in order:
    temp = []
    for i in item:
        if i=="F":
            temp.append("R")
        elif i=="R"
            temp.append("F")
        else:
            temp.append(i)
    order_1.append(temp)