figure node object contains the item and reference to the next node figure typical representation for node def get_next(self)return self next def set_data(selfnew_data)self data newdata def set_next(selfnew_next)self next new_next we create node objects in the usual way temp node( temp get_data( the special python reference value none will play an important role in the node class and later in the linked list itself reference to none will denote the fact that there is no next node note in the constructor that node is initially created with next set to none since this is sometimes referred to as "grounding the node,we will use the standard ground symbol to denote reference that is referring to none it is always good idea to explicitly assign none to your initial next reference values the unordered list class as we suggested abovethe unordered list will be built from collection of nodeseach linked to the next by explicit references as long as we know where to find the first node (containing the first item)each item after that can be found by successively following the next links with this in mindthe unorderedlist class must maintain reference to the first node the following code shows the constructor note that each list object will maintain single reference to the head of the list class unorderedlist basic data structures