Using Python to Set GitHub Action Outputs

The output format of GitHub Action is to write {name}={value} to the environment variable GITHUB_OUTPUT^[1][2] This article shares how to set up the GitHub Action output using Python. The main content comes from this discussion^[3].

Singleline

import os
name = 'my_name'
value = 'my_value'
with open(os.environ['GITHUB_OUTPUT'], 'a') as fh:
    print(f'{name}={value}', file=fh)

Multiline

import uuid

def set_multiline_output(name, value):
    with open(os.environ['GITHUB_OUTPUT'], 'a') as fh:
        delimiter = uuid.uuid1()
        print(f'{name}<<{delimiter}', file=fh)
        print(value, file=fh)
        print(delimiter, file=fh)

Just call it with

set_multiline_output("value", my_multiline_string)

References

1. Workflow commands for GitHub Actions. Archived on 2024-09-06. Retrieved 2024-09-06. ↩
2. GitHub Actions: Deprecating save-state and set-output commands. Archived on 2024-09-06. Retrieved 2024-09-06. ↩
3. How to set-output from a python script in Github workflow step. #28146. Archived on 2024-09-06. Retrieved 2024-09-06. ↩