Скачать или смотреть Efficiently Insert Key-Value Pairs from List of Dictionaries Based on Common Keys in Python

Learn how to efficiently merge key-value pairs from multiple lists of dictionaries in Python using an optimized approach.
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Efficiently Insert Key-Value Pairs from One List of Dictionaries to Another in Python

If you’re working with lists of dictionaries in Python, you may find yourself needing to merge data based on common keys. For instance, suppose you have a large list of dictionaries representing products, and you want to enrich this dataset with corresponding total values from one or more additional dictionaries based on a common key.

In this guide, we will take you through a step-by-step process to achieve this efficiently by utilizing Python's dictionaries and loops.

Problem Overview

Imagine you have a list of dictionaries like this:

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

And you have a couple of other lists with total values:

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

The challenge is to efficiently merge the total1 and total2 values into big_list_dictionary, based on the name value, whilst handling the fact that the name in big_list_dictionary includes an extra = 1.

Optimized Solution Steps

Step 1: Create an Intermediate Dictionary

We will create an intermediate dictionary that strips the unwanted characters (= 1) from the name. This will allow us to easily match the names across the dictionaries.

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

Step 2: Merge the Total Values

Using the intermediate dictionary, we will iterate through total1 and total2, adding the total values back to the corresponding items in our intermediate structure.

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

Step 3: Finalize the List

After merging the values, your big_list_dictionary will look like this:

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

The output will be:

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

Performance Benchmarking

The code snippet provided performs significantly better compared to nested loops. Running a time benchmark showed that the optimized method took approximately 513 µs, while the initial solution took 91.6 ms.

Handling Additional Items

If there are names in either total1 or total2 that are not in big_list_dictionary, you can add more checks and append these new items accordingly. Here’s a way to do that:

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

Conclusion

This method efficiently enhances your main list of dictionaries with additional values based on common keys, relying on an intermediate structure to streamline the merging process. Optimizing your approach will not only save time but also ensure that your code runs smoothly, even when handling larger datasets.

Feel free to experiment with the solution and adapt it to your specific data structure or requirements!