python 实现无序列表

 # -*- coding:utf-8 -*-
 class Node:
     def __init__(self, initdata):
         self.data = initdata
         self.next = None

     def getData(self):
         return self.data

     def getNext(self):
         return self.next

     def setData(self, newdata):
         self.data = newdata

     def setNext(self, newnext):
         self.next = newnext

 class UnorderedList:
     def __init__(self):
         self.head = None

     def isEmpty(self):
         return self.head == None

     def add(self, item):
         temp = Node(item)
         temp.setNext(self.head)
         self.head = temp

     def size(self):
         current = self.head
         count = 0
         while current != None:
             count = count + 1
             current = current.getNext()
         return count

     def travel(self):
         current = self.head
         while current != None:
             print current.getData()
             current = current.getNext()

     def search(self, item):
         current = self.head
         found = False
         while current != None and not found:
             if current.getData() == item:
                 found = True
             else:
                 current = current.getNext()
         return found

     def remove(self, item):
         current = self.head
         previous = None
         found = False
         while not found:
             if current.getData() == item:
                 found = True
             else:
                 previous = current
                 current = current.getNext()
         if previous == None:
             self.head = current.getNext()
         else:
             previous.setNext(current.getNext())

     def append(self, item):
         temp = Node(item)
         if self.isEmpty():
             self.head = temp
         else:
             current = self.head
             while current.getNext() != None:
                 current = current.getNext()
             current.setNext(temp)

     def index(self, item):
         current = self.head
         count = 0
         found = False
         while current != None and not found:
             count += 1
             if current.getData() == item:
                 found = True
             else:
                 current = current.getNext()
         if found:
             return count
         else:
             raise ValueError, '%s is not in this unorderedList' %item

     def insert(self, pos, item):
         if pos <= 1:
             self.add(item)
         elif pos > self.size():
             self.append(item)
         else:
             temp = Node(item)
             count = 1
             previous = None
             current = self.head
             while count < pos:
                 count += 1
                 previous = current
                 current = current.getNext()
             previous.setNext(temp)
             temp.setNext(current)

 if __name__ == '__main__':
     t = UnorderedList()
     for i in range(10):
         t.append(i)
     print t.size()
     t.travel()
     print t.search(5)
     print t.index(3)
     t.remove(8)
     t.travel()
     t.insert(2, 12)
     t.travel()