recursion for in lstaccumulator [xaccumulator return accumulator def main()print(revlist([ , , , ]) if __name__ ="__main__"main(when runthis program prints [ to the screen the code in sect uses the accumulator pattern to solve the problem of reversing list this is pattern you have probably used before if you first learned to program imperatively if we think about the problem recursivelywe would first consider how to reverse very simple listsay the empty list the reverse of the empty list is just the empty list once we have solved the problem for very simple listwe can assume that if we call recursive reverse function on something smaller ( shorter list)it will work sothen to complete recursive solutionwe have only to piece our solution together recursive solution to reversing list is found in sect reversing list def revlist(lst)here is the base case if lst =[]return [ the rest of this function is the recursive case this works because we called it on something smaller the lst[ :is slice of all but the first item in lst restrev revlist(lst[ :]first lst[ : now put the pieces together result restrev first return result def main()print(revlist([ , , , ]) if __name__ ="__main__"main(you can write recursive functions that work with strings too strings and lists are both sequences in the code of sect we made sure we recursively called our function on something smaller the same is true when working with strings string reverse function is given in sect this copy belongs to 'acha