How to Merge Multiple Dictionaries in Python with Repeating Keys

Learn how to efficiently merge multiple dictionaries with repeating keys in Python, ensuring all values are captured in one unified dictionary.
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Merging Multiple Dictionaries in Python with Repeating Keys

In Python, working with dictionaries is a common task, especially when you have to manage multiple data points. But what happens when you need to merge multiple dictionaries that contain repeating keys? This can be a challenge as standard merging methods could overwrite data. In this guide, we will explore how to effectively combine dictionaries while preserving all values associated with those keys.

The Problem

Imagine you have several dictionaries, each containing data with common keys. For example, consider the following dictionaries:

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

Your goal is to merge these dictionaries so that you retain all the values associated with each key. The desired output would look like this:

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

The Solution

To achieve this, we can utilize the defaultdict from the collections module. This allows us to specify a default data type for our dictionary, automatically initializing keys with an empty list when they do not exist. Consequently, we can simplify our merging process significantly without having to check if a key exists before appending to it. Let's break this down step by step.

Step-by-Step Guide

Import defaultdict:
We start by importing defaultdict from the collections module.

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

Define the Dictionaries:
You can define your dictionaries as shown above.

Create a Merging Function:
We will write a function called merge_dicts that accepts any number of dictionaries as arguments. This function will handle the merging process for us.

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

Call the Function and Print the Result:
Finally, you can call the function with the dictionaries you want to merge and print the result.

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

Code Overview

Here's the complete code snippet for your reference:

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

Conclusion

Merging multiple dictionaries with repeating keys doesn’t have to be complicated. By using defaultdict from the collections module, you can easily aggregate and retain all values associated with the same keys. Whether you're dealing with a small set of dictionaries or larger datasets, this approach scales well and simplifies your code.

Now that you have this tool in your Python toolbox, you are better equipped to handle dictionary merging tasks with ease! Happy coding!