---
title: "Working With Python's deque – Real Python"
url: https://daily.dev/posts/working-with-python-s-deque-real-python-dcumr7pcz
source_url: https://realpython.com/courses/working-with-pythons-deque
type: article
source: "Real Python"
published: 2026-08-18T14:11:58.211Z
updated: 2026-08-18T14:27:55.294Z
tags: ["python", "data-structures"]
reading_time: 2
upvotes: 0
comments: 0
language: en
---

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# Working With Python's deque – Real Python

**[Real Python](https://daily.dev/sources/rpython)** · 2 min read · 0 upvotes · 0 comments

## Summary

A video course covering Python's deque data structure, explaining how it uses a doubly linked list internally for O(1) appends and pops at both ends versus O(n) for list operations. It shows how to build FIFO queues and LIFO stacks, use maxlen for bounded history buffers, and notes that core deque operations are thread-safe in CPython for producer-consumer patterns. Includes video lessons, transcripts, exercises, and a quiz.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://realpython.com/courses/working-with-pythons-deque>

## Questions this post answers

### When should I use a Python deque instead of a list for a queue?

Use deque when you need efficient appends and pops from both ends, since deque operations at either end run in O(1) time due to its internal doubly linked list, while a list requires O(n) time to remove or insert at the front. Deque supports indexing but not slicing, and is ideal for FIFO queues, LIFO stacks, and bounded history buffers.

_Developers weighing list versus deque for performance-critical code can dig deeper into data structure trade-offs on daily.dev._

### How do I limit the size of a Python deque so old items get dropped automatically?

Pass a value to the maxlen parameter when creating the deque to create a bounded deque. Once the deque reaches that length, adding new items automatically drops items from the opposite end, making it useful for maintaining a fixed-size history buffer without manual trimming.

_Anyone building history buffers or sliding windows can find more Python patterns like this on daily.dev._

### Are Python deque append and pop operations thread-safe?

Yes, in CPython the deque operations append(), appendleft(), pop(), popleft(), and len() are thread-safe, making deque a solid choice for multithreaded producer-consumer setups without needing extra locking around these specific operations.

_Developers designing thread-safe producer-consumer pipelines can track Python concurrency tips on daily.dev._

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---

Tags: [#python](https://daily.dev/tags/python), [#data-structures](https://daily.dev/tags/data-structures)

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