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Priority Queue Implementation in Python: Easily Sort and Manage Data


Python Priority Queue Implementation

Queues are a fundamental data structure that is extensively used in computer science and software development. In Python, there are several built-in queue implementations, including the priority queue. In this tutorial, we will explore priority queue implementation in Python, understand its use cases, and learn to utilize it effectively.

Learning About the Types of Queues

Before diving into the details of priority queue implementation, let’s first understand the different types of queues in computer science. This will provide us with a foundation to build upon.

  1. Queue: First-In, First-Out (FIFO)
  2. Stack: Last-In, First-Out (LIFO)
  3. Deque: Double-Ended Queue
  4. Priority Queue: Sorted From High to Low

Implementing Queues in Python

Now that we have a basic understanding of the different types of queues, let’s move on to implementing them in Python. In this section, we will explore how to represent FIFO and LIFO queues using a deque, as well as build custom queue and stack data types.

  1. Representing FIFO and LIFO Queues With a Deque
  2. Building a Queue Data Type
  3. Building a Stack Data Type
  4. Representing Priority Queues With a Heap
  5. Building a Priority Queue Data Type
  6. Handling Corner Cases in Your Priority Queue
  7. Refactoring the Code Using a Mixin Class

Using Queues in Practice

Queues are not just an abstract concept - they have practical applications. In this section, we will explore how to use queues in real-world scenarios, such as implementing various graph algorithms and utilizing breadth-first search, depth-first search, and Dijkstra’s algorithm.

  1. Sample Data: Road Map of the United Kingdom
  2. Object Representation of the Cities and Roads
  3. Breadth-First Search Using a FIFO Queue
  4. Shortest Path Using Breadth-First Traversal
  5. Depth-First Search Using a LIFO Queue
  6. Dijkstra’s Algorithm Using a Priority Queue

Using Thread-Safe Queues

In multi-threaded environments, it is crucial to ensure the thread safety of shared data structures. Python provides several thread-safe queue implementations that can be used to address this concern. In this section, we will explore the queue.Queue, queue.LifoQueue, and queue.PriorityQueue classes.

Using Asynchronous Queues

When working with asynchronous programming in Python, it is essential to have queues that can handle concurrent operations seamlessly. In this section, we will explore the asyncio module, which provides several queue classes suitable for asynchronous programming, such as asyncio.Queue, asyncio.LifoQueue, and asyncio.PriorityQueue.

Using multiprocessing.Queue for Interprocess Communication (IPC)

Python’s multiprocessing module allows for executing code across multiple processes, and it provides the multiprocessing.Queue class for interprocess communication. In this section, we will learn how to utilize this class for various scenarios, such as reversing an MD5 hash, distributing workload evenly, and communicating in full-duplex mode.

Integrating Python With Distributed Message Queues

In modern distributed systems, message queues play a vital role in facilitating communication between different components. In this section, we will explore how to integrate Python with popular distributed message queue brokers, such as RabbitMQ, Redis, and Apache Kafka, using the respective libraries (pika, redis, kafka-python3).


In this tutorial, we have learned about the different types of queues and explored their implementation in Python. We have seen how to build custom queue and stack data types, as well as utilize thread-safe and asynchronous queues. Additionally, we have explored practical use cases for queues, such as implementing graph algorithms and integrating with distributed message queues.

By mastering priority queue implementation and effectively utilizing queues in your Python programs, you can improve the efficiency and scalability of your applications. Queues are powerful tools that can help you solve a wide range of problems, making them an essential concept for any Python developer to understand.