How to clear a multiprocessing queue in python

Question

I just want to know how to clear a multiprocessing queue in python like a normal python queue. For instance:

from multiprocessing import Queue  # multiprocessing queue from Queue import Queue            # normal queue  multi_q = Queue() normal_q = Queue() multi_q.clear()                    # or multi_q.queue.clear()  

'Queue' object has no attribute 'clear'

normal_q.queue.clear() # This is ok 

Answer 1

So, I take look at Queue class, and you may to try this code:

while not some_queue.empty():     some_queue.get()  # as docs say: Remove and return an item from the queue. 

Answer 2

Ask for forgiveness rather than permission; just try to empty the queue until you get the Empty exception, then ignore that exception:

from Queue import Empty  def clear(q):     try:         while True:             q.get_nowait()     except Empty:         pass 

Better yet: is a built-in class missing the method you want? Subclass the built-in class, and add the method you think should be there!

from Queue import Queue, Empty  class ClearableQueue(Queue):      def clear(self):         try:             while True:                 self.get_nowait()         except Empty:             pass 

Your ClearableQueue class inherits all the goodness (and behavior) of the built-in Queue class, and has the method you now want.

Simply use q = ClearableQueue() in all places where you used q = Queue(), and call q.clear() when you'd like.