Recently installed Python 3.8 (from 2.7) on Windows 10, and all my scripts didn't work anymore. For some strange reason 

> python -s script.py args

would put the args into sys.argv[], while

> script.py args

would only show the script in sys.argv[]. I found this report which fixed the problem: 

https://stackoverflow.com/questions/15281951/sys-argv-contents-when-calling-python-script-implicitly-on-windows

(Basically, the .py(w) association in the registry need an additional '%*' parameter to pass the script parameters.)

So I assume the Python 3 Windows installer overwrote my earlier registry associations. 

The other way the problem happened could be that the Python 3 installer did not change the registry assocation to 3.8, and I did this manually. I verified that setting a "default program" for windows will put the deficient association (without argument passing) into the registry. 

Either way, I would expect that after installing Python 3.8, my scripts would really run with 3.8, and with their arguments. :-) 

Danke & Grüße von 
nobi