Скачать или смотреть How to Check if a Column Item is Also an Item of a List in Python Pandas

Learn how to efficiently check if values in a Pandas DataFrame column exist in a list, and update those values accordingly.
---
This video is based on the question https://stackoverflow.com/q/67414411/ asked by the user 'Grinnorye' ( https://stackoverflow.com/u/15175594/ ) and on the answer https://stackoverflow.com/a/67415250/ provided by the user 'lprakashv' ( https://stackoverflow.com/u/4066802/ ) 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: python pandas: How to check if a column item is also item of a 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.
---
How to Check if a Column Item is Also an Item of a List in Python Pandas: A Step-by-Step Guide

In data analysis, you may find yourself needing to filter or modify values in a DataFrame based on whether they exist in a specific list. This task can be straightforward, provided you have the right techniques in place. In this guide, we will explore how to efficiently check if items in a Pandas DataFrame column match items in a given list, and how to perform updates based on this condition.

Understanding the Problem

Let's start with the example of a DataFrame constructed using two columns, list1 and list2.

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

Suppose we have a list, entries_to_met, containing specific values we want to check against the column list1:

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

Our goal is to modify the corresponding entries in list2 where the values in list1 match any value from entries_to_met. Specifically, we want to add 15 to list2 for those matching rows.

Solution Walkthrough

To implement this, we can make use of the isin() method, which is very efficient for this purpose. Here’s how we can achieve our goal:

Step 1: Import Libraries

First, ensure you have the necessary libraries imported.

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

Step 2: Create the DataFrame

We will create our DataFrame as shown earlier:

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

Step 3: Define the Condition

Next, define our list of conditions:

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

Step 4: Update the DataFrame

We will use the loc method along with isin() to perform a Conditional Update. Here’s the magic piece of code:

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

Step 5: Check the Result

After running the above line, you can print the modified DataFrame to see the changes:

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

The final DataFrame should look like this:

list1list2001111722333194455521Conclusion

In this guide, we've effectively shown how to check if items in a DataFrame column exist in a list, and how to update the DataFrame based on those checks using Pandas. This approach is not only efficient but also simplifies code readability and maintainability.

Feel free to experiment with this method, and integrate it into your own data manipulation tasks. Happy coding!