five data structures this describes some things you've learned about already in more detailand adds some new things as well more on lists the list data type has some more methods here are all of the methods of list objectslist append(xadd an item to the end of the list equivalent to [len( ):[xlist extend(iterableextend the list by appending all the items from the iterable equivalent to [len( ):iterable list insert(ixinsert an item at given position the first argument is the index of the element before which to insertso insert( xinserts at the front of the listand insert(len( )xis equivalent to append(xlist remove(xremove the first item from the list whose value is equal to it raises valueerror if there is no such item list pop([ ]remove the item at the given position in the listand return it if no index is specifieda pop(removes and returns the last item in the list (the square brackets around the in the method signature denote that the parameter is optionalnot that you should type square brackets at that position you will see this notation frequently in the python library reference list clear(remove all items from the list equivalent to del [:list index( [start [end ]]return zero-based index in the list of the first item whose value is equal to raises valueerror if there is no such item the optional arguments start and end are interpreted as in the slice notation and are used to limit the search to particular subsequence of the list the returned index is computed relative to the beginning of the full sequence rather than the start argument list count(xreturn the number of times appears in the list list sort(key=nonereverse=falsesort the items of the list in place (the arguments can be used for sort customizationsee sorted(for their explanation