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    <p>Alex's approach is great. I won't pretend to compete with his level of expertise, but for sake of completeness, here is another approach using the fantastic <a href="http://docs.python.org/library/queue.html" rel="nofollow noreferrer"><code>Queue.Queue</code></a> class (bonus: thread-safe, but that's kinda useless to you based on your description). This might be easier to understand for you, as you expressed some concern on that point:</p> <h3>myqueue.py</h3> <pre><code>#!/usr/bin/python # Renamed in Python 3.0 try: from Queue import Queue, Full, Empty except: from queue import Queue, Full, Empty from datetime import datetime # Spec 1: Size of each queue should be user-defined. # - maxsize on __init__ # Spec 2: Date an object is added should be recorded. # - datetime.now() is first member of tuple, data is second # Spec 3: I would like to be able to define the order of the items that # belong to each queue. # - Order cannot be rearranged with this queue. # Spec 4: If the queue is full, the addition of an extra item should discard # the oldest item of the queue. # - implemented in put() class MyQueue(Queue): "Wrapper around Queue that discards old items instead of blocking." def __init__(self, maxsize=10): assert type(maxsize) is int, "maxsize should be an integer" Queue.__init__(self, maxsize) def put(self, item): "Put an item into the queue, possibly discarding an old item." try: Queue.put(self, (datetime.now(), item), False) except Full: # If we're full, pop an item off and add on the end. Queue.get(self, False) Queue.put(self, (datetime.now(), item), False) def put_nowait(self, item): "Put an item into the queue, possibly discarding an old item." self.put(item) def get(self): "Get a tuple containing an item and the datetime it was entered." try: return Queue.get(self, False) except Empty: return None def get_nowait(self): "Get a tuple containing an item and the datetime it was entered." return self.get() def main(): "Simple test method, showing at least spec #4 working." queue = MyQueue(5) for i in range(1, 7): queue.put("Test item number %u" % i) while not queue.empty(): time_and_data = queue.get() print "%s =&gt; %s" % time_and_data if __name__ == "__main__": main() </code></pre> <h3>expected output</h3> <pre><code>2009-11-02 23:18:37.518586 =&gt; Test item number 2 2009-11-02 23:18:37.518600 =&gt; Test item number 3 2009-11-02 23:18:37.518612 =&gt; Test item number 4 2009-11-02 23:18:37.518625 =&gt; Test item number 5 2009-11-02 23:18:37.518655 =&gt; Test item number 6 </code></pre>
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    1. POHow to create queues of objects in Django?
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    1. USJed Smith
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    1. COHi Jed. This is an excellent example of how to modify the default Queue class. Thanks for writing it :) Some things still puzzle me though about how to implement a queue with the above functionality using Django's models and the admin app, for example what django element should represent the queue? Should it be a record in a table? Should it be an inline in ModelAdmin (with max_num equal to the size of the queue)?
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    2. CO@Born: I'm teaching myself Django next weekend (never gotten around to it), so I'm not sure. (Halp, other commenters!)
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    3. CO@Jed: I guess I've chosen a difficult task to accomplish as a n00b! :D
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