Deserialize YAML into Python Class Instances without Using Tags

Discover how to deserialize YAML files into Python class instances based on their content without relying on tags. This guide offers practical examples to help you work efficiently with Kubernetes objects.
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Deserialize YAML into Python Class Instances without Using Tags: A Step-by-Step Guide

Understanding the Challenge

Imagine you have a folder filled with .yaml files containing different Kubernetes objects. Your goal is to read these files, deserialize the contents based on a key called kind, and create instances of the appropriate Python classes. The added complexity is to preserve comments and formatting from the original YAML files.

Example YAML Files

Here are a couple of example YAML files you might encounter:

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

In this blog, we’ll outline a solution that allows you to achieve this deserialization without relying on the traditional YAML tagging method.

Step-by-Step Solution

1. Set Up Your Project

Start by creating the necessary Python classes. Each class will inherit from a base class designed to handle YAML comments and formatting.

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

2. Create a Mapping for Class Instances

To effectively map the kind values to your classes, create a dictionary that associates each kind with its corresponding class.

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

3. Implement the Unkind Function

Next, you'll need a function that recursively traverses the dictionary or list structure of the YAML data to replace each entry with the appropriate class instance based on the kind key.

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

4. Read and Deserialize YAML Files

Now, you can read your YAML files and call the un_kind function to deserialize them into the defined Python class instances.

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

5. Example Output

When running the above code on the example YAML files, the output will display the transformed Python objects, preserving the original comment and formatting.

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

Conclusion

With this approach, you’re now equipped to handle varying types of Kubernetes objects within your Python applications efficiently.