Скачать или смотреть How to Subset a DataFrame Based on Specific Substrings in Python's pandas

Learn how to filter rows in a pandas DataFrame to find those that contain specific substrings in their columns.
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Subsetting a DataFrame with Specific Substrings Using Python’s Pandas

When working with data in Python, especially using the pandas library, we often encounter scenarios where we need to filter rows based on specific criteria. One such common requirement is selecting rows from a DataFrame that contain specific substrings in their columns while ignoring rows that contain other substrings. In this guide, we will explore how to achieve this using a practical example.

The Problem at Hand

Assume we have a DataFrame called df that looks like this:

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

We are tasked with selecting rows that contain the substrings Coin and Charge, while ensuring that the other columns do not have the substrings Bill or Other, which indicates that they should either be empty or non-existent in those rows. The expected result would be:

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

The Solution

To tackle this problem, we'll leverage the powerful functionality of the pandas library to apply a lambda function across our DataFrame. Let’s break down the solution into easy-to-understand steps.

Step 1: Filtering Rows Using Lambda Function

We can use the apply function along with a custom lambda function to check each row for our needed conditions. Below is the code to achieve this:

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

Step 2: Verifying Substring Presence

The above approach works when searching for whole strings. However, if we want to search for substrings like Coin (quarters) instead of just Coin, we need a slightly different approach. Here's how you can adjust your function to check for substrings:

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

Step 3: Output

Both methods above should yield similar outputs, showing only the rows of interest. For our example DataFrame, the expected output would be:

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

Conclusion

Filtering rows in a DataFrame based on specific substrings might seem tricky at first, but with the power of Python's pandas, we can accomplish this with ease. By using the apply function and a custom lambda function, we can precisely control which rows to include in our final subset. Whether you're searching for whole strings or substrings, following the steps outlined above will enable you to handle similar data filtering tasks effectively.

Now you can tackle your DataFrame filtering tasks with confidence! Happy coding!