1 class doubleLinkedList(object):
2     class doubleLinkedNode(object):
3         def __init__(self, data, pre = None, next = None):
4             self.info = data
5             self.pre = pre
6             self.next =  next
7        def getInfo(self):
8           return self.info
9        def setInfo(self, value):
10            self.info = value
11       def getNext(self):
12           return self.next
13       def setNext(self, ptr):
14           self.next = ptr
15       def getPre(self):
16           return self.pre
17       def setPre(self, ptr):
18           self.pre = ptr  
19    #----------------------------
20    def __init__(self): 
21        self.head = None   #Start of list
22        self.last = None   #End of list
23        self.size = 0   #Size of list
24    def  __del__(self):
25
26    def getSize(self):
27        return self.size
28    def isEmpty(self):
29        return self.head == None
30
32    def searchNode(self, data):
32
33    def insertAtFirst(self, newNode):
34
35    def insertAtLast(self, newNode):
36 
37    def insertAfterNode(self, newNode, item):
38
39    def deleteNode(self, data):
40
41    def traverse(self):
42
43    def backwardTraverse(self):





                       
               









        
    
