Sys.argv command line parsing (documentation)

[petersuter]

CMD redirects PY code to new window that disappears

CMD’s assoc and ftype commands are outdated. They were introduced back in Windows NT 4.0 (1996) and haven’t been significantly updated since then. They only show and modify the system software classes in “HKLM\Software\Classes”, for a given file type (e.g. “.py”) or given programmatic identifier (e.g. “Python.File”). A lot has changed since 1996. File associations can be defined in many places in the registry: HKCU\Software\Classes [HKCU|HKLM]\Software\Classes\Applications [HKCU|HKLM]\Softwar…

This is probably what you want to look at instead:

in the settings for “Apps → Default apps”