Python 实现有序单向链表

#!/usr/bin/python # -*- coding: utf-8 -*-'''Created on 2015-1-22@author: beyondzhou@name: test_sortedsinglelinkedlist.py'''def test_sortedsinglelinkedlist():        # import linkedlist    from sortedsinglelinkedlist import sortedsingleLinkedList        # init a linkedlist named smith    smith = sortedsingleLinkedList()    smith.add('CSCI-112')    smith.add('MATH-121')    smith.add('HIST-340')    smith.add('ECON-101')        # print smith    print 'primary smith'    for item in smith:        print item            # remove one item    smith.remove('HIST-340')        # print smith    print '\ndeleted smith'    for item in smith:        print item            # pring length    print '\nlenght of smith'    print len(smith)        # check whether not in    print '\ncheck whether not in'    print 'abc' in smith     # check whether in    print '\ncheck whether in'    print 'ECON-101' in smith               if __name__ == "__main__":    test_sortedsinglelinkedlist()

# Implements the linked listclass sortedsingleLinkedList:    # constructs an empty linked list    def __init__(self):        self._head = None        self._size = 0    # Returns the number of items in the linked list    def __len__(self):        return self._size    # Determines if an item is contained in the linked list    def __contains__(self, target):        curNode = self._head        while curNode is not None and curNode.item != target:            curNode = curNode.next        return curNode is not None    # Adds a new item to the linked list    def add(self, item):        predNode = None        curNode = self._head        while curNode is not None and item > curNode.item:            predNode = curNode            curNode = curNode.next        # Create the new node for the new value        newNode = _LinkedListNode(item)        newNode.next = curNode        # Link the new node into the list        if curNode is self._head:            self._head = newNode        else:            predNode.next = newNode        self._size += 1    # Removes an instance of the item from the linked list    def remove(self, item):        predNode = None        curNode = self._head        while curNode is not None and item > curNode.item:            predNode = curNode            curNode = curNode.next                # The item has to be in the linked list to remove it        assert curNode is not None, "The item must be in the linked list."                # Unlink the node and return the item        self._size -= 1        if curNode is self._head:            self._head = curNode.next        else:            predNode.next = curNode.next        return curNode.item    # Returns an iterator for traversing the list of items    def __iter__(self):        return _LinkedListIterator(self._head)# Defines a private storage clss for creating list nodesclass _LinkedListNode(object):    def __init__(self, item):        self.item = item        self.next = None# Defines a linked list iterator class _LinkedListIterator:    def __init__(self, listHead):        self._curNode = listHead    def __iter__(self):        return self    def next(self):        if self._curNode is None:            raise StopIteration        else:            item = self._curNode.item            self._curNode = self._curNode.next            return item

primary smithCSCI-112ECON-101HIST-340MATH-121deleted smithCSCI-112ECON-101MATH-121lenght of smith3check whether not inFalsecheck whether inTrue