## 7.5.1 Queue Objects

Class `Queue` implements queue objects and has the methods described below. This class can be derived from in order to implement other queue organizations (e.g. stack) but the inheritable interface is not described here. See the source code for details. The public interface methods are:

`__init__` (maxsize)
  Constructor for the class. maxsize is an integer that sets the upperbound limit on the number of items that can be placed in the queue. Insertion will block once this size has been reached, until queue items are consumed. If maxsize is less than or equal to zero, the queue size is infinite.

`qsize` ()
  Returns the approximate size of the queue. Because of multithreading semantics, this number is not reliable.

`empty` ()
  Returns 1 if the queue is empty, 0 otherwise. Because of multithreading semantics, this is not reliable.

`full` ()
  Returns 1 if the queue is full, 0 otherwise. Because of multithreading semantics, this is not reliable.

`put` (item)
  Puts item into the queue.

`get` ()
  Gets and returns an item from the queue, blocking if necessary until one is available.

`get_nowait` ()
  Gets and returns an item from the queue if one is immediately available. Raises an `Empty` exception if the queue is empty or if the queue's emptiness cannot be determined.