The following could be used to add Python. Upstream Python only provides source based downloads and requires building from source. Requires GCC and some other build-time dependancies. I might use Drone CICD for building Python and then just copy the artifacts into my dev environment.
```Dockerfile
# Install Python
RUN curl -L -O https://www.python.org/ftp/python/3.9.0/Python-3.9.0.tar.xz && \