This one made me smile. From: http://aima.cs.berkeley.edu/python/utils.html#Queue
class Queue: """Queue is an abstract class/interface. There are three types: Stack(): A Last In First Out Queue. FIFOQueue(): A First In First Out Queue. PriorityQueue(lt): Queue where items are sorted by lt, (default <). Each type supports the following methods and functions: q.append(item) -- add an item to the queue q.extend(items) -- equivalent to: for item in items: q.append(item) q.pop() -- return the top item from the queue len(q) -- number of items in q (also q.__len()) Note that isinstance(Stack(), Queue) is false, because we implement stacks as lists. If Python ever gets interfaces, Queue will be an interface.""" def __init__(self): abstract def extend(self, items): for item in items: self.append(item) -- http://mail.python.org/mailman/listinfo/python-list