Скачать или смотреть How to Take User Input to Create a Stack in Python with a XXX Termination Signal

Learn how to efficiently collect user inputs into a stack in Python until the user types `XXX` to end the entry. This guide covers both list and deque data structures.
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This video is based on the question https://stackoverflow.com/q/69415497/ asked by the user 'cemod vvdgre' ( https://stackoverflow.com/u/17057254/ ) and on the answer https://stackoverflow.com/a/69415614/ provided by the user 'meta_geek' ( https://stackoverflow.com/u/13922656/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Take User Input to Create a Stack in Python with a XXX Termination Signal

When working with user inputs in Python, it's common to need a way to collect data until a specific termination input is provided. In this post, we will explore a practical solution to take user inputs and store them in a stack structure until the user decides to stop by entering XXX.

Understanding the Problem

The goal here is to create a stack that allows users to enter multiple values, and when they want to end their input, they simply enter XXX. Here's how the input process may look:

Prompt: Enter element, 'XXX' to end:

User Input: a

Prompt: Enter element, 'XXX' to end:

User Input: b

Prompt: Enter element, 'XXX' to end:

User Input: c

Prompt: Enter element, 'XXX' to end:

User Input: XXX (This input ends the process)

The Solution

Using Python Lists

One of the simplest ways to create a stack in Python is by using a list. Here's a step-by-step breakdown of how this can be done:

Initialize an empty list to hold your stack.

Use a while loop to keep prompting the user for input until XXX is entered.

Append each valid entry to the list.

Stop prompting when the user enters XXX.

Here’s how the code looks:

[[See Video to Reveal this Text or Code Snippet]]

Using Collections.deque

For better performance, especially with larger datasets, you might want to use collections.deque. Deque is optimized for fast appends and pops from both ends. Here's how you can implement the same logic using deque:

Import deque from the collections module.

Initialize deque instead of a list.

Follow the same logic as above for taking inputs.

Here’s the modified code:

[[See Video to Reveal this Text or Code Snippet]]

Popping Elements from the Stack

Once you have collected the inputs in your stack, you might want to access them or remove the last item added. You can use the pop() method to do this easily, regardless of whether you are using a list or deque.

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

In this article, we explored how to take user inputs in Python to form a stack structure until a termination signal (XXX) is received. By using either a list or a deque, you can efficiently handle user input in a way that is easy to understand and implement.

If you're looking to work with stacks in Python, remember that deque offers greater efficiency, especially for larger datasets. So go ahead and try it out in your own projects!