Python 使用list實現隊列 (基於class, 包含迭代器)，pythonlist

Python 使用list實現隊列 (基於class, 包含迭代器)，pythonlist

#!/usr/bin/python # -*- coding: utf-8 -*-'''Created on 2015-1-27@author: beyondzhou@name: test_listqueue.py'''def test_listqueue():        # import pyListQueue    from myqueue import pyListQueue        print '#Init a queue named smith using enqueue'    smith = pyListQueue()    smith.enqueue('CSCI-112')    smith.enqueue('MATH-121')    smith.enqueue('HIST-340')    smith.enqueue('ECON-101')        print '\n#output smith queue'    for element in smith:        print element               print '\n#dequeue one item'    smith.dequeue()        print '\n#output smith after dequeue'    for element in smith:        print element             print '\n#get the length of queue'    print 'the lenght of queue is ', len(smith)        print '\n#check wheter the queue is empty'    if smith.isEmpty():        print 'queue is empty!'    else:        print 'queue is not empty!'            print '\n#dequeue all items'    while not smith.isEmpty():        smith.dequeue()        print '\n#check wheter the queue is empty after dequeue all items'    if smith.isEmpty():        print 'queue is empty!'    else:        print 'queue is not empty!'    if __name__ == "__main__":    test_listqueue()

# Implementation of iterclass _pyListQueueIterator:    def __init__(self, theList):        self._setItems = theList        self._curItem = 0    def __iter__(self):        return self    def next(self):        if self._curItem < len(self._setItems):            item = self._setItems[self._curItem]            self._curItem += 1            return item        else:            raise StopIteration        # Implementation of the Queue ADT using a Python listclass pyListQueue:    # Creates an empty queue    def __init__(self):        self._qList = list()    # Returns True if the queue is empty    def isEmpty(self):        return len(self) == 0    # Returns the number of items in the queue    def __len__(self):        return len(self._qList)    # Adds the given item to the queue    def enqueue(self, item):        self._qList.append(item)    # Removes and returns the first item in the queue    def dequeue(self):        assert not self.isEmpty(), "Cannot dequeue from an empty queue."        return self._qList.pop(0)    # Returns an iterator for traversing the list of items    def __iter__(self):        return _pyListQueueIterator(self._qList)

#Init a queue named smith using enqueue#output smith queueCSCI-112MATH-121HIST-340ECON-101#dequeue one item#output smith after dequeueMATH-121HIST-340ECON-101#get the length of queuethe lenght of queue is  3#check wheter the queue is emptyqueue is not empty!#dequeue all items#check wheter the queue is empty after dequeue all itemsqueue is empty!