How to Install Python 3.9 in Azure Webjobs?

Install a Custom Python Version:

If Python 3.9 is not pre-installed, you can deploy it manually:

a. Download Python 3.9

Download a portable version of Python 3.9 (Windows-compatible ZIP) from the official Python website or a trusted source.
Unzip the file and place it in a directory under your WebJob (e.g., site/wwwroot/python39).

b. Add Python 3.9 to Path

Use Kudu to edit the App Service's environment variables.
Go to the Configuration > General settings > Path mappings in your App Service.
Add the Python executable directory (site/wwwroot/python39) to the PATH environment variable.

c. Set Python Version in WebJob

In the WebJob configuration (e.g., a run.cmd or run.bat script), ensure the custom Python path is used. Example:

set PATH=%HOME%\site\wwwroot\python39;%PATH%
python --version
python your_script.py