#----------------------- def add1Modify(L): for i in range(len(L)): # must use range, since we need the index L[i] += 1 return L #----------------------- def add1Copy(L): LCopy = [] for num in L: # we don't need index here, so don't need range() LCopy += [num+1] return LCopy # Note: if we have a copy of L, we can safely modify the copy def add1Copy2(L): LCopy = L[:] # Copy all the elements of L by slicing return add1Modify(LCopy)