https://docs.python.org/3.7/using/windows.html#windows-store
>The Microsoft Store package is a simple installation of Python that is suitable for running scripts and packages, and using IDLE or other development environments. It requires Windows 10, but can be safely installed without corrupting other programs. It also provides many convenient commands for launching Python and its tools.
> Note The Microsoft Store package is currently considered unstable while its interactions with other tools and other copies of Python are evaluated. While Python itself is stable, this installation method may change its behavior and capabilities during Python 3.7 releases.
It is "an" official method, not the preferred official method, and most certainly not "the" official method.
https://docs.python.org/3.8/using/windows.html#windows-store