Get length of Queue in Python's multiprocessing library
If the queue you are talking about is multiprocessing.Queue, try to use qsize() method for multiprocessing.Queue objects, but be careful:
qsize()
Return the approximate size of the queue. Because of multithreading/multiprocessing semantics, this number is not reliable.
Note that this may raise NotImplementedError on Unix platforms like Mac OS X where sem_getvalue() is not implemented.