How to Extract Substrings from Left to Specific Character in a Pandas DataFrame

Learn how to efficiently extract substrings from a pandas DataFrame by targeting specific characters. This guide will help you manipulate string data for various needs!
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How to Extract Substrings from Left to Specific Character in a Pandas DataFrame

When working with data in pandas, especially with string columns, you may encounter a common problem: extracting portions of a string up to a certain character. For instance, if you have a DataFrame populated with strings like "oop9-hg78-op67_457y", you might want to remove everything from the underscore _ to the end of the string to align it with another dataset. In this guide, we will explore how to achieve this in a simple and efficient manner.

Understanding the Problem

Imagine you have a DataFrame structured as follows:

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You need to manipulate the column such that everything after the _ is removed. The desired output would be:

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

Solution Overview

Here's how to do it:

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

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

Explanation of Each Method

By assigning .str[0] to df['column'], it selects the first element of these split lists (the part before the underscore).

The expression ^([^_]*)_ means:

^ asserts the start of the string.

([^_]*) captures any characters that are not an underscore and stores them in a group.

_ matches the underscore itself to ensure we capture only the desired part of the string.

Conclusion