Which Implementation Should You Use for Stacks In Python?

Python Stacks and Threading

Let me just recap what I've read about how to implement Stacks in python so far.

There are 2 options to create a stack in python whether using lists or deques and both of them behave differently if your program has threads.

It's a better sweet not to use lists to implement Stacks or any data structure that can be accessed by multiple threads as lists is not thread-safe. List can potentially have memory reallocation issues and it makes you build the entire functionality of the stacks on your own.

deaues is a thread-safe more than list, even if it's more complex than lists, according to queue class documentation, it clearly states that both the .append()and .pop() operations are atomic, meaning that they won’t be interrupted by a different thread.

So, while it’s possible to build a thread-safe Python stack 
using a deque, doing so exposes yourself to someone misusing
 it in the future and causing race conditions.

For this use LifoQueue from queue module.

LifoQueue is designed to be fully thread-safe. All of its methods are safe to use in a threaded environment.

EX

from queue import LifoQueue
myStack = LifoQueue()

myStack.put('a')
myStack.put('b')
myStack.put('c')

myStack


myStack.get()

myStack.get()

myStack.get()


# myStack.get() <--- waits forever
myStack.get_nowait()

In notes :

• Use a deque if you’re not using threading.

• If your program has threads, then you should use a LifoQueue

• The interface of both list and deque are the same ,yet deque doesn’t have memory allocation issues, which makes deque the best choice for your non-threaded Python stack.