new format of output in custom GitHub Actions since set-output is going to be deprecated

Question

As per GitHub's recent announcement, github action's set-output is going to be deprecated next year. I was able to use the new format (echo "{name}={value}" >> $GITHUB_OUTPUT) in workflow file, and it works. But we also have a custom GitHub action(private one) written in python and we are also using set-output there in main.py as:

                output_matrix = json.dumps(jsondata)
                print(f"::set-output name=output_matrix::{output_matrix}")

What I have tried so far is :

print(f"output_matrix = {output_matrix} >> $GITHUB_OUTPUT")

but this doesn't seem to help. Any solution how we can use set-output's new format inside custom github action python file.

Answer 1

I made a test here using this workflow implementation and this python script.

What you can do in a python script is the same implementation for outputs variables as for environments variables.

Example for ENVIRONMENTS variables: (here is another topic about it)

import os

env_file = os.getenv('GITHUB_ENV')

hello='hello'

with open(env_file, "a") as myfile:
    myfile.write(f"TEST={hello}")

Example for OUTPUTS variables:

import os

output_file = os.getenv('GITHUB_OUTPUT')

hello='hello'
    
with open(output_file, "a") as myfile:
    myfile.write(f"TEST={hello}")

Note that this implementation was working even before the update regarding the ::set-output depreciation.