collections queue python - Brave Search

queue.Queue vs. collections.deque

stackoverflow.com › questions › 717148 › queue-queue-vs-collections-deque

queue.Queue and collections.deque serve different purposes. queue.Queue is intended for allowing different threads to communicate using queued messages/data, whereas collections.deque is simply intended as a data structure. That's why queue.Queue has methods like put_nowait(), get_nowait(), and join(), whereas collections.deque doesn't. queue.Queue isn't intended to be used as a collection, which is why it lacks the likes of the in operator.

It boils down to this: if you have multiple threads and you want them to be able to communicate without the need for locks, you're looking for queue.Queue; if you just want a queue or a double-ended queue as a datastructure, use collections.deque.

Finally, accessing and manipulating the internal deque of a queue.Queue is playing with fire - you really don't want to be doing that.

Answer from Keith Gaughan on Stack Overflow

docs.python.org › 3 › library › collections.html

collections — Container datatypes

class collections.deque([iterable[, maxlen]])¶ · Returns a new deque object initialized left-to-right (using append()) with data from iterable. If iterable is not specified, the new deque is empty. Deques are a generalization of stacks and queues (the name is pronounced “deck” and is short for “double-ended queue”).

stackoverflow.com › questions › 717148 › queue-queue-vs-collections-deque

python - queue.Queue vs. collections.deque - Stack Overflow

queue.Queue and collections.deque serve different purposes. queue.Queue is intended for allowing different threads to communicate using queued messages/data, whereas collections.deque is simply intended as a data structure. That's why queue.Queue has methods like put_nowait(), get_nowait(), and join(), whereas collections.deque doesn't. queue.Queue isn't intended to be used as a collection, which is why it lacks the likes of the in operator.

It boils down to this: if you have multiple threads and you want them to be able to communicate without the need for locks, you're looking for queue.Queue; if you just want a queue or a double-ended queue as a datastructure, use collections.deque.

Finally, accessing and manipulating the internal deque of a queue.Queue is playing with fire - you really don't want to be doing that.

If all you're looking for is a thread-safe way to transfer objects between threads, then both would work (both for FIFO and LIFO). For FIFO:

Queue.put() and Queue.get() are thread-safe
Deques support thread-safe, memory efficient appends and pops from either side of the deque with approximately the same O(1) performance in either direction.

Note:

Other operations on deque might not be thread safe, I'm not sure.
deque does not block on pop() or popleft() so you can't base your consumer thread flow on blocking till a new item arrives.

However, it seems that deque has a significant efficiency advantage. Here are some benchmark results in seconds using CPython 2.7.3 for inserting and removing 100k items

deque 0.0747888759791
Queue 1.60079066852

Here's the benchmark code:

import time
import Queue
import collections

q = collections.deque()
t0 = time.clock()
for i in xrange(100000):
    q.append(1)
for i in xrange(100000):
    q.popleft()
print 'deque', time.clock() - t0

q = Queue.Queue(200000)
t0 = time.clock()
for i in xrange(100000):
    q.put(1)
for i in xrange(100000):
    q.get()
print 'Queue', time.clock() - t0

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geeksforgeeks.org › python › deque-in-python

Deque in Python - GeeksforGeeks

A deque stands for Double-Ended Queue. It is a special type of data structure that allows to add and remove elements from both ends efficiently. This makes it useful in applications like task scheduling, sliding window problems and real-time data processing. Python · from collections import deque de = deque(['name','age','DOB']) print(de) Output ·

Published December 11, 2025

dataquest.io › blog › python-deque-queues-stacks

Python Deque Function: A Better Choice for Queues and Stacks – Dataquest

April 7, 2025 - If you use Python, you're probably familiar with lists, and you probably use them a lot, too. They're great data structures with many helpful methods that allow the user to modify the list by adding, removing, and sorting items. However, there are some use cases when a list may look like a great choice, but it just isn't. That is where the deque() function (short for double-ended queue, pronounced like "deck") from the collections module can be a much better choice when you need to implement queues and stacks in Python.

docs.circuitpython.org › en › latest › docs › library › collections.html

collections – collection and container types — Adafruit CircuitPython 1 documentation

class collections.deque(iterable, maxlen[, flag]) · Deques (pronounced “deck” and short for “double-ended queue”) are fixed length list-like containers that support O(1) appends and pops from either side of the deque.

codesignal.com › learn › courses › advanced-built-in-data-structures-and-their-usage › lessons › understanding-queues-and-deques-in-python

Understanding Queues and Deques in Python

A deque, or "double-ended queue", allows the addition and removal of items from both ends. Python provides the collections module containing the deque class for implementing deques.

docs.python.org › 3 › library › queue.html

queue — A synchronized queue class

February 23, 2026 - collections.deque is an alternative implementation of unbounded queues with fast atomic append() and popleft() operations that do not require locking and also support indexing. ... © Copyright 2001 Python Software Foundation.

geeksforgeeks.org › python › creating-queue-using-collections-deque-in-python

Creating Queue Using Collections.Deque In Python - GeeksforGeeks

July 23, 2025 - In Python, Queue and Deque are the data structures used for managing collections of elements in a first-in, first-out (FIFO) manner.

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medium.com › @sanjula99perera › efficient-queue-implementation-in-python-using-collections-deque-2446908ffa34

“Efficient Queue Implementation in Python Using collections.deque” | by Sanjulaperera | Medium

May 28, 2024 - Initial queue: ['a', 'b', 'c'] Elements dequeued from queue: a b c Queue after removing elements: [] ... The deque class from the collections module provides an efficient way to implement a queue.

realpython.com › python-deque

Python's deque: Implement Efficient Queues and Stacks – Real Python

January 12, 2026 - It implements multi-producer, ... abstractions over deque unless you’re implementing your own data structure. Queues are collections of items....

note.nkmk.me › home › python

How to Use Deque in Python: collections.deque | note.nkmk.me

April 20, 2025 - In Python, the collections.deque class provides an efficient way to handle data as a queue, stack, or deque (double-ended queue). collections - deque objects — Container datatypes — Python 3.13.3 do ...

codecademy.com › docs › python › deque

Python | Deque | Codecademy

April 10, 2025 - A deque is a double-ended queue implementation in Python’s collections module. It provides a versatile data structure that generalizes a stack and a queue by allowing efficient append and pop operations from both ends of the sequence.

rico-schmidt.name › pymotw-3 › collections › deque.html

deque — Cola doblemente terminada — El módulo Python 3 de la semana

$ python3 collections_deque_populating.py extend : deque(['a', 'b', 'c', 'd', 'e', 'f', 'g']) append : deque(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']) extendleft: deque([5, 4, 3, 2, 1, 0]) appendleft: deque([6, 5, 4, 3, 2, 1, 0])

educative.io › answers › how-to-implement-a-queue-in-python

How to implement a queue in Python

We have used the following methods ... False. ... The collections.deque module in Python provides a double-ended queue (deque) that allows adding and removing elements efficiently from both ends....

medium.com › @shras_a › queue-in-python-34a74641502e

Queue in Python. Queues are fundamental data structures… | by Shravya | Medium

November 14, 2024 - This article will walk you through the basics of queues, their types, and how to work with them in Python. ... FIFO Queue: First In, First Out. Processing items in arrival order (e.g., task scheduling). Example: queue.Queue or collections.deque.

mygreatlearning.com › blog › it/software development › python queue

October 14, 2024 - OUTPUT: <queue.Queue object at ... a double-ended queue. The double-ended queue or deque is used to support the insertion and deletion of elements from both the ends such as the Front and Rear ends....

medium.com › cloud-for-everybody › stop-using-lists-for-queues-and-stacks-in-python-use-deque-instead-7c9619802ca0

Stop Using Lists for Queues in Python: Use Deque Instead

March 1, 2026 - A practical guide to using collections.deque in Python to build efficient, clean, and fast queue data structures

datagy.io › home › python collections › python collections deque – stacks and queues

Python Collections deque - Stacks and Queues • datagy

December 16, 2022 - Python deque’s also provide a great opportunity to rotate, or shuffle, items. This means that the items in the queue are pushed forward or backward a certain number of items. We can use the .rotate() method to pass in a positive or negative integer to rotate the items in the deque. Let’s see what happens when we instantiate a deque with the numbers 1 through 5 and rotate it: # Rotating a Deque's Items from collections import deque queue = deque([1, 2, 3, 4, 5]) queue.rotate(1) print(queue) # Returns: # deque([5, 1, 2, 3, 4])

squash.io › python-deque-understanding-the-doubly-ended-queue

How to Use the Doubly Ended Queue (Deque) with Python

July 9, 2023 - To create a deque in Python, you can use the collections module that comes with the standard library. The collections module provides a class called deque which represents a double-ended queue.

altcademy.com › blog › what-built-in-python-data-type-is-best-suited-for-implementing-a-queue

what built-in Python data type is best suited for implementing a queue

January 30, 2024 - In this example, documents are ... In the world of Python programming, the deque from the collections module is your go-to data type for implementing an efficient and fast queue....