this works well if you only need to read the elements of the list but if you want to write or update the elementsyou need the indices common way to do that is to combine the functions range and lenfor in range(len(numbers))numbers[inumbers[ this loop traverses the list and updates each element len returns the number of elements in the list range returns list of indices from to where is the length of the list each time through the loopi gets the index of the next element the assignment statement in the body uses to read the old value of the element and to assign the new value for loop over an empty list never executes the bodyfor in emptyprint('this never happens 'although list can contain another listthe nested list still counts as single element the length of this list is four['spam' ['brie''roquefort''pol le veq'][ ] list operations the operator concatenates listsa [ [ print( [ similarlythe operator repeats list given number of times[ [ [ [ the first example repeats four times the second example repeats the list three times