Python/winrt support for python 3.8 version

[snippsat]

There is an Issue rapport here.

There are several way you use 3.7 and don't touch your Python 3.8 installation.
Just install python 3.7 from here,do not add to Environment Variables Path.
Then install with py -3.7 -m pip install winrt.

E:\div_code
λ py -3.7 -m pip install winrt
Collecting winrt
  Downloading winrt-1.0.19128.1-cp37-none-win32.whl (4.6 MB)
     |████████████████████████████████| 4.6 MB 2.2 MB/s
Installing collected packages: winrt
Successfully installed winrt-1.0.19128.1

# Test that it work
E:\div_code
λ py -3.7
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import winrt.windows.foundation as wf
>>> 
>>> u = wf.Uri("https://github.com/")
>>> u.host
'github.com'

I still have Python 3.8 as main version in path,but using py can access all other version.

E:\div_code
λ python -V
Python 3.8.3

E:\div_code
λ pip -V
pip 20.1.1 from c:\python38\lib\site-packages\pip (python 3.8)

---

Using Anaconda example the smaller version Miniconda
This is a stand alone version that are Python 3.7,so here can just install normal with pip.
Do this from Scripts where pip are.

G:\mini_conda37\Scripts
λ pip -V
pip 20.0.2 from G:\mini_conda37\lib\site-packages\pip (python 3.7)

G:\mini_conda37\Scripts
λ pip install winrt
Collecting winrt
  Downloading winrt-1.0.19128.1-cp37-none-win_amd64.whl (3.9 MB)
     |████████████████████████████████| 3.9 MB 1.3 MB/s
Installing collected packages: winrt
Successfully installed winrt-1.0.19128.1

With conda can also create virtual environment for a specific Python version wanted.

conda create -n myenv python=3.7