How to Diff JSON Files and Update Changes Using Python

Learn how to diff two JSON files in Python and update them with only the changes. Discover best practices and helpful code snippets here!
---

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: Diff json files and write changes

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Diff JSON Files and Update Changes Using Python

When working with JSON files, you may often need to compare two files to identify their differences. This can be essential for maintaining configuration files, data synchronization, or simply keeping your data clean. In this guide, we’ll explore how to diff two JSON files using Python and update them efficiently based on the differences found.

Problem Introduction

Imagine you have two JSON files, and you want to ensure that the second file reflects any changes made in the first file, but without rewriting the entire file. For instance, let’s say we have:

File One (the source of truth):

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

File Two (the one you want to update):

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

In this case, the only difference lay in the id field of the secure object. The goal is to only update the id in File Two without unnecessarily affecting the other fields.

Our Solution: Using jsondiff Library

To achieve this, we will leverage the jsondiff library in Python. This library provides a convenient way to find differences between two JSON structures. Below, I will walk you through a step-by-step implementation of this solution.

Step 1: Install jsondiff

Before we start coding, ensure you have the jsondiff library installed. You can do this using pip:

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

Step 2: Import Required Libraries

In your Python script, you’ll need to import the necessary libraries:

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

Step 3: Load JSON Files

Load the JSON files that you want to compare. Set up your function to handle the files specified through command line arguments.

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

Step 4: Finding the Differences

Utilize the diff function to find the differences between the two JSON objects. You can hold the differences in a variable for further processing.

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

Step 5: Updating the Differences

Utilize the updates found to modify the second JSON object:

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

Step 6: Write Updates back to File

Finally, you will want to save the updated content back to the second file. Create or overwrite the second JSON file with the updates:

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

Complete Code Example

Here’s the complete code snippet based on the above steps:

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

Conclusion

Using Python and the jsondiff library, you can efficiently identify and update differences between two JSON files. This method allows for a streamlined process that focuses on altering only the necessary parts of the second file, ensuring that you maintain any other existing data. If you encounter any issues or have questions, feel free to leave a comment below! Happy coding!