Скачать или смотреть How to Compare and Append Minimum Values from Two Lists in Python

A step-by-step guide on how to compare items at the same index between two lists in Python and append the minimum values to a third list using simple code examples.
---
This video is based on the question https://stackoverflow.com/q/66646378/ asked by the user 'Andrei Radulescu' ( https://stackoverflow.com/u/10420903/ ) and on the answer https://stackoverflow.com/a/66646447/ provided by the user 'James' ( https://stackoverflow.com/u/5003756/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Compare items at the same index between 2 lists and append the min value to a 3rd list?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Comparing Items at Same Index in Two Lists: A Simple Guide

Working with lists in Python can be both rewarding and challenging. One common problem that programmers face is comparing items at the same index between two lists and appending the smallest value to a third list. If you've ever found yourself tangled in a complex loop trying to address this issue, don't worry! In this post, we'll explore an easy solution that makes use of Python's built-in functions.

The Problem

Let's imagine we have two lists:

arr_1 = [5, 9, 3]

arr_2 = [2, 16, 4]

We want to compare these two lists element by element (index by index) and create a third list, arr_3, that will hold the minimum values from the two. In our example, the expected output should be arr_3 = [2, 9, 3], where:

The first values (5 and 2) compare, giving us 2.

The second values (9 and 16) give us 9.

The third values (3 and 4) result in 3.

The Solution

Now, let's break down the solution into clear steps.

Using a For Loop and zip()

We can simply leverage the zip() function to pair up the lists and a for loop to iterate through these pairs. Here’s how the function looks:

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

Breaking It Down:

zip(arr_1, arr_2): This creates pairs of values from arr_1 and arr_2, allowing us to compare them directly.

for num1, num2 in: This loop iterates over each pair from the zipped lists.

min(num1, num2): The min() function returns the smaller of the two numbers.

arr_3.append(min(num1, num2)): This line appends the smaller value to our result list arr_3.

The Efficient Way: Using map()

Alternatively, we can make our function even more concise by utilizing map():

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

Explanation:

map(min, zip(arr_1, arr_2)): This applies the min function to each pair produced by zip(), effectively returning an iterable of minimum values.

list(): This converts the iterable back into a list.

Summary

Comparing items in two lists can be streamlined in Python using zip() and built-in functions like min(). Here’s a recap of our findings:

Use a simple loop with zip() for clarity.

Employ map() for a concise and Pythonic approach.

Now, with these methods, you'll be well-equipped to solve similar problems in your coding journey!

Conclusion

In this guide, we covered a straightforward way to compare two lists index-by-index and append the smallest values to a third list in Python. Whether you choose to go with the loop-based method or the more concise map(), understanding how to manipulate lists is a skill that will serve you well in your programming efforts.

That’s it for today! Happy coding!