# queue - pydoc - phpman Help on module queue: ## NAME queue - A multi-producer, multi-consumer queue. ## MODULE REFERENCE The following documentation is automatically generated from the Python source files. It may be incomplete, incorrect or include features that are considered implementation detail and may vary between Python implementations. When in doubt, consult the module reference at the location listed above. ## CLASSES builtins.Exception(builtins.BaseException) _queue.Empty Full builtins.object _queue.SimpleQueue Queue LifoQueue PriorityQueue ### class Empty | Exception raised by Queue.get(block=0)/get_nowait(). | | Method resolution order: | Empty | builtins.Exception | builtins.BaseException | builtins.object | | Data descriptors defined here: | | __weakref__ | list of weak references to the object (if defined) | | ---------------------------------------------------------------------- | Methods inherited from builtins.Exception: | | __init__(self, /, *args, **kwargs) | Initialize self. See help(type(self)) for accurate signature. | | ---------------------------------------------------------------------- | Static methods inherited from builtins.Exception: | | __new__(*args, **kwargs) from builtins.type | Create and return a new object. See help(type) for accurate signature. | | ---------------------------------------------------------------------- | Methods inherited from builtins.BaseException: | | __delattr__(self, name, /) | Implement delattr(self, name). | | __getattribute__(self, name, /) | Return getattr(self, name). | | __reduce__(...) | Helper for pickle. | | __repr__(self, /) | Return repr(self). | | __setattr__(self, name, value, /) | Implement setattr(self, name, value). | | __setstate__(...) | | __str__(self, /) | Return str(self). | | with_traceback(...) | Exception.with_traceback(tb) -- | set self.__traceback__ to tb and return self. | | ---------------------------------------------------------------------- | Data descriptors inherited from builtins.BaseException: | | __cause__ | exception cause | | __context__ | exception context | | __dict__ | | __suppress_context__ | | __traceback__ | | args ### class Full | Exception raised by Queue.put(block=0)/put_nowait(). | | Method resolution order: | Full | builtins.Exception | builtins.BaseException | builtins.object | | Data descriptors defined here: | | __weakref__ | list of weak references to the object (if defined) | | ---------------------------------------------------------------------- | Methods inherited from builtins.Exception: | | __init__(self, /, *args, **kwargs) | Initialize self. See help(type(self)) for accurate signature. | | ---------------------------------------------------------------------- | Static methods inherited from builtins.Exception: | | __new__(*args, **kwargs) from builtins.type | Create and return a new object. See help(type) for accurate signature. | | ---------------------------------------------------------------------- | Methods inherited from builtins.BaseException: | | __delattr__(self, name, /) | Implement delattr(self, name). | | __getattribute__(self, name, /) | Return getattr(self, name). | | __reduce__(...) | Helper for pickle. | | __repr__(self, /) | Return repr(self). | | __setattr__(self, name, value, /) | Implement setattr(self, name, value). | | __setstate__(...) | | __str__(self, /) | Return str(self). | | with_traceback(...) | Exception.with_traceback(tb) -- | set self.__traceback__ to tb and return self. | | ---------------------------------------------------------------------- | Data descriptors inherited from builtins.BaseException: | | __cause__ | exception cause | | __context__ | exception context | | __dict__ | | __suppress_context__ | | __traceback__ | | args ### class LifoQueue | LifoQueue(maxsize=0) | | Variant of Queue that retrieves most recently added entries first. | | Method resolution order: | LifoQueue | Queue | builtins.object | | Methods inherited from Queue: | | __init__(self, maxsize=0) | Initialize self. See help(type(self)) for accurate signature. | | empty(self) | Return True if the queue is empty, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() == 0 | as a direct substitute, but be aware that either approach risks a race | condition where a queue can grow before the result of empty() or | qsize() can be used. | | To create code that needs to wait for all queued tasks to be | completed, the preferred technique is to use the join() method. | | full(self) | Return True if the queue is full, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() >= n | as a direct substitute, but be aware that either approach risks a race | condition where a queue can shrink before the result of full() or | qsize() can be used. | | get(self, block=True, timeout=None) | Remove and return an item from the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until an item is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Empty exception if no item was available within that time. | Otherwise ('block' is false), return an item if one is immediately | available, else raise the Empty exception ('timeout' is ignored | in that case). | | get_nowait(self) | Remove and return an item from the queue without blocking. | | Only get an item if one is immediately available. Otherwise | raise the Empty exception. | | join(self) | Blocks until all items in the Queue have been gotten and processed. | | The count of unfinished tasks goes up whenever an item is added to the | queue. The count goes down whenever a consumer thread calls task_done() | to indicate the item was retrieved and all work on it is complete. | | When the count of unfinished tasks drops to zero, join() unblocks. | | put(self, item, block=True, timeout=None) | Put an item into the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until a free slot is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Full exception if no free slot was available within that time. | Otherwise ('block' is false), put an item on the queue if a free slot | is immediately available, else raise the Full exception ('timeout' | is ignored in that case). | | put_nowait(self, item) | Put an item into the queue without blocking. | | Only enqueue the item if a free slot is immediately available. | Otherwise raise the Full exception. | | qsize(self) | Return the approximate size of the queue (not reliable!). | | task_done(self) | Indicate that a formerly enqueued task is complete. | | Used by Queue consumer threads. For each get() used to fetch a task, | a subsequent call to task_done() tells the queue that the processing | on the task is complete. | | If a join() is currently blocking, it will resume when all items | have been processed (meaning that a task_done() call was received | for every item that had been put() into the queue). | | Raises a ValueError if called more times than there were items | placed in the queue. | | ---------------------------------------------------------------------- | Class methods inherited from Queue: | | __class_getitem__ = GenericAlias(...) from builtins.type | Represent a PEP 585 generic type | | E.g. for t = list[int], t.__origin__ is list and t.__args__ is (int,). | | ---------------------------------------------------------------------- | Data descriptors inherited from Queue: | | __dict__ | dictionary for instance variables (if defined) | | __weakref__ | list of weak references to the object (if defined) ### class PriorityQueue | PriorityQueue(maxsize=0) | | Variant of Queue that retrieves open entries in priority order (lowest first). | | Entries are typically tuples of the form: (priority number, data). | | Method resolution order: | PriorityQueue | Queue | builtins.object | | Methods inherited from Queue: | | __init__(self, maxsize=0) | Initialize self. See help(type(self)) for accurate signature. | | empty(self) | Return True if the queue is empty, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() == 0 | as a direct substitute, but be aware that either approach risks a race | condition where a queue can grow before the result of empty() or | qsize() can be used. | | To create code that needs to wait for all queued tasks to be | completed, the preferred technique is to use the join() method. | | full(self) | Return True if the queue is full, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() >= n | as a direct substitute, but be aware that either approach risks a race | condition where a queue can shrink before the result of full() or | qsize() can be used. | | get(self, block=True, timeout=None) | Remove and return an item from the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until an item is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Empty exception if no item was available within that time. | Otherwise ('block' is false), return an item if one is immediately | available, else raise the Empty exception ('timeout' is ignored | in that case). | | get_nowait(self) | Remove and return an item from the queue without blocking. | | Only get an item if one is immediately available. Otherwise | raise the Empty exception. | | join(self) | Blocks until all items in the Queue have been gotten and processed. | | The count of unfinished tasks goes up whenever an item is added to the | queue. The count goes down whenever a consumer thread calls task_done() | to indicate the item was retrieved and all work on it is complete. | | When the count of unfinished tasks drops to zero, join() unblocks. | | put(self, item, block=True, timeout=None) | Put an item into the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until a free slot is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Full exception if no free slot was available within that time. | Otherwise ('block' is false), put an item on the queue if a free slot | is immediately available, else raise the Full exception ('timeout' | is ignored in that case). | | put_nowait(self, item) | Put an item into the queue without blocking. | | Only enqueue the item if a free slot is immediately available. | Otherwise raise the Full exception. | | qsize(self) | Return the approximate size of the queue (not reliable!). | | task_done(self) | Indicate that a formerly enqueued task is complete. | | Used by Queue consumer threads. For each get() used to fetch a task, | a subsequent call to task_done() tells the queue that the processing | on the task is complete. | | If a join() is currently blocking, it will resume when all items | have been processed (meaning that a task_done() call was received | for every item that had been put() into the queue). | | Raises a ValueError if called more times than there were items | placed in the queue. | | ---------------------------------------------------------------------- | Class methods inherited from Queue: | | __class_getitem__ = GenericAlias(...) from builtins.type | Represent a PEP 585 generic type | | E.g. for t = list[int], t.__origin__ is list and t.__args__ is (int,). | | ---------------------------------------------------------------------- | Data descriptors inherited from Queue: | | __dict__ | dictionary for instance variables (if defined) | | __weakref__ | list of weak references to the object (if defined) ### class Queue | Queue(maxsize=0) | | Create a queue object with a given maximum size. | | If maxsize is <= 0, the queue size is infinite. | | Methods defined here: | | __init__(self, maxsize=0) | Initialize self. See help(type(self)) for accurate signature. | | empty(self) | Return True if the queue is empty, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() == 0 | as a direct substitute, but be aware that either approach risks a race | condition where a queue can grow before the result of empty() or | qsize() can be used. | | To create code that needs to wait for all queued tasks to be | completed, the preferred technique is to use the join() method. | | full(self) | Return True if the queue is full, False otherwise (not reliable!). | | This method is likely to be removed at some point. Use qsize() >= n | as a direct substitute, but be aware that either approach risks a race | condition where a queue can shrink before the result of full() or | qsize() can be used. | | get(self, block=True, timeout=None) | Remove and return an item from the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until an item is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Empty exception if no item was available within that time. | Otherwise ('block' is false), return an item if one is immediately | available, else raise the Empty exception ('timeout' is ignored | in that case). | | get_nowait(self) | Remove and return an item from the queue without blocking. | | Only get an item if one is immediately available. Otherwise | raise the Empty exception. | | join(self) | Blocks until all items in the Queue have been gotten and processed. | | The count of unfinished tasks goes up whenever an item is added to the | queue. The count goes down whenever a consumer thread calls task_done() | to indicate the item was retrieved and all work on it is complete. | | When the count of unfinished tasks drops to zero, join() unblocks. | | put(self, item, block=True, timeout=None) | Put an item into the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until a free slot is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Full exception if no free slot was available within that time. | Otherwise ('block' is false), put an item on the queue if a free slot | is immediately available, else raise the Full exception ('timeout' | is ignored in that case). | | put_nowait(self, item) | Put an item into the queue without blocking. | | Only enqueue the item if a free slot is immediately available. | Otherwise raise the Full exception. | | qsize(self) | Return the approximate size of the queue (not reliable!). | | task_done(self) | Indicate that a formerly enqueued task is complete. | | Used by Queue consumer threads. For each get() used to fetch a task, | a subsequent call to task_done() tells the queue that the processing | on the task is complete. | | If a join() is currently blocking, it will resume when all items | have been processed (meaning that a task_done() call was received | for every item that had been put() into the queue). | | Raises a ValueError if called more times than there were items | placed in the queue. | | ---------------------------------------------------------------------- | Class methods defined here: | | __class_getitem__ = GenericAlias(...) from builtins.type | Represent a PEP 585 generic type | | E.g. for t = list[int], t.__origin__ is list and t.__args__ is (int,). | | ---------------------------------------------------------------------- | Data descriptors defined here: | | __dict__ | dictionary for instance variables (if defined) | | __weakref__ | list of weak references to the object (if defined) ### class SimpleQueue | Simple, unbounded, reentrant FIFO queue. | | Methods defined here: | | empty(self, /) | Return True if the queue is empty, False otherwise (not reliable!). | | get(self, /, block=True, timeout=None) | Remove and return an item from the queue. | | If optional args 'block' is true and 'timeout' is None (the default), | block if necessary until an item is available. If 'timeout' is | a non-negative number, it blocks at most 'timeout' seconds and raises | the Empty exception if no item was available within that time. | Otherwise ('block' is false), return an item if one is immediately | available, else raise the Empty exception ('timeout' is ignored | in that case). | | get_nowait(self, /) | Remove and return an item from the queue without blocking. | | Only get an item if one is immediately available. Otherwise | raise the Empty exception. | | put(self, /, item, block=True, timeout=None) | Put the item on the queue. | | The optional 'block' and 'timeout' arguments are ignored, as this method | never blocks. They are provided for compatibility with the Queue class. | | put_nowait(self, /, item) | Put an item into the queue without blocking. | | This is exactly equivalent to `put(item)` and is only provided | for compatibility with the Queue class. | | qsize(self, /) | Return the approximate size of the queue (not reliable!). | | ---------------------------------------------------------------------- | Class methods defined here: | | __class_getitem__(...) from builtins.type | See PEP 585 | | ---------------------------------------------------------------------- | Static methods defined here: | | __new__(*args, **kwargs) from builtins.type | Create and return a new object. See help(type) for accurate signature. ## DATA __all__ = ['Empty', 'Full', 'Queue', 'PriorityQueue', 'LifoQueue', 'Si... ## FILE /usr/lib/python3.10/queue.py