Скачать или смотреть Mastering Python: How to Concatenate Dictionaries with Same Keys

Learn the efficient way to `merge two dictionaries` in Python while retaining all their values, using concise code and dictionary comprehension.
---
This video is based on the question https://stackoverflow.com/q/66455260/ asked by the user 'Random Rush Girl' ( https://stackoverflow.com/u/14761246/ ) and on the answer https://stackoverflow.com/a/66455547/ provided by the user 'Alain T.' ( https://stackoverflow.com/u/5237560/ ) 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: How do I concatenate 2 dictionaries which have the same keys, while retaining all the values?

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.
---
Mastering Python: How to Concatenate Dictionaries with Same Keys

In the world of Python programming, dictionaries are versatile data structures that allow you to store and manipulate key-value pairs conveniently. But what happens when you want to combine two dictionaries that have the same keys? This can be a common challenge, especially for amateur coders. In this guide, we will tackle the question: How do I concatenate 2 dictionaries which have the same keys, while retaining all the values?

The Problem

Let's consider the following scenario:

You have two dictionaries, d1 and d2, structured as follows:

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

The goal is to merge these two dictionaries into one new dictionary d, such that it looks like this:

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

Current Approach

Your existing code utilizes a brute force method, which can be inefficient for larger dictionaries:

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

This method works, but it’s not the most elegant solution. Fortunately, there's a more efficient way to achieve our objectives using Python’s powerful programming features.

The Solution: Using Dictionary Comprehension

A much more efficient approach is to utilize dictionary comprehension. This allows for a more concise and readable way of merging dictionaries.

Step-by-Step Explanation

Combine Values: Use the * operator to unpack values from both dictionaries.

Enumerate: The enumerate() function will help us generate sequential keys for our merged dictionary automatically.

Create the New Dictionary: We will iterate over the combined values and assign them new keys in the desired format.

Implementation

Here's how you can implement this solution in code:

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

Breakdown of the Code

(*d1.values(), *d2.values()): This unpacks all the values from both dictionaries into a single tuple.

enumerate(..., 1): The 1 here assigns the starting index for our key construction. This means the first element is associated with the key 1, the second with the key 2, and so forth.

{ str(i): v for i, v in ...}: This constructs the new dictionary by assigning the generated keys to the combined values.

Conclusion

Merging dictionaries with the same keys may initially appear daunting, but with Python’s capabilities, it can be done efficiently and elegantly. By leveraging dictionary comprehension and the enumerate() function, you can create a clean and functional solution to retain all values from both dictionaries.

With these powerful tools at your disposal, you can streamline your programming tasks and improve your code readability. Happy coding!