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()