Mar 6, 2025 · A deque stands for Double-Ended Queue. It is a data structure that allows adding and removing elements from both ends efficiently. Unlike regular queues, which are typically operated on using FIFO (First In, First Out) principles, a deque supports both FIFO and LIFO (Last In, First Out) operations. Example: Python

Python’s collections module provides a class called deque that’s specially designed to provide fast and memory-efficient ways to append and pop item from both ends of the underlying data structure.

Apr 24, 2024 · In this article, we will learn to implement queues using collections.deque in Python. Below, is the Implementation of Creating Queue Using Collections.Deque in Python: In the below step, we import the deque class from the collections module using the statement from the collections import deque.

Aug 21, 2018 · In Python 3.9, you can use deque['MyClass']() directly. If you are using Python 3.6.1 or higher, you can use typing.Deque: pass. return myqueue.popleft() global_queue.append(MyClass()) Alternatively, you can do global_queue = Deque['MyClass']() instead -- at runtime, that'll construct a collections.deque object.

3 days ago · A ChainMap class is provided for quickly linking a number of mappings so they can be treated as a single unit. It is often much faster than creating a new dictionary and running multiple update() calls. The class can be used to simulate nested scopes and is …

I have a class, and I need to implement a queue; pushing to the left, and popping from the right (FIFO). def __init__(self, a, b): self._a = a # integer . self._b = b # string. def number(self): return self._a. def name(self): return self._b. c1 = X(100, "red") c2 = X(200, "blue") ... que = deque() que.appendleft(c1) que.appendleft(c2) ...

Apr 20, 2025 · In Python, the collections.deque class provides an efficient way to handle data as a queue, stack, or deque (double-ended queue). While the built-in list can be used as a queue, stack, or deque, collections.deque offers better performance, especially for adding or removing elements at the beginning.

In this article, we'll explore the deque data structure in detail, including its features, use cases, and how to use it effectively in your Python programs. We'll also provide code examples to illustrate its functionality.

Jun 2, 2021 · To implement deque using list, we will have to insert and delete elements from both sides of the list. We can also perform operations like checking the length of the deque or checking if the deque is empty. For this task we will use a dequeSize method to keep the count of the number of elements in the deque.

Jun 1, 2022 · In Python, we can use the collections.deque class to implement a deque. The deque class is a general-purpose, flexible and efficient sequence type that supports thread-safe, memory efficient appends and pops from either side. A deque provides approximately O (1) time complexity for append and pop opeations in either direction.