the loops in iterable, and converting between types

for x in iterable_string/list/list_item/tuple/tuple_item:

            deal with ......

list ---> string,  ''.join(list1, list2, list3, ...)

string ---> list, string.split('delimiter or empty space')

list ---> tuple, tuple(list)

tuple--->list, list(tuple)

int ---> string,  str(int)

'integer' string ---> int, int('integer')