Default .py program and Edit with IDLE problem

[Rick Johnson]

alister wrote:
> Steve D'Aprano wrote:
> > Rick Johnson wrote:
[...]

> I think to a point I have to agree with rick, 

Well, alister, i'll take what i can get around here. :-)

> windows installers can be flaky and time is money.

Indeed.

> if something does not work after installation (& does not
> gibe any clues as to why) a quick install (reboot) & re
> install is work a try & probably has a 25-50% success rate.

Well, part of the problem here is that OP failed to provide
the necessary information. Ssorry OP, but i gotta call you
out on this one!

First of all, the OP made it sound as though the Python3
install was working all fine-and-dandy until Python2 was
installed, then some command-line hackery became problematic
with "some errors i didn't used to get"  --- whatever that
means...

Then after uninstalling Python2, the OP reports some weird
OS specific behavior about icons disappearing and missing
commands from the Windows Contextual Menu. Okay, the later
issue would seem to indicate that the system file
associations related to Python had been deleted and that the
Python 2.x uninstaller, being unaware that the Python3 would
hang around for a while longer, did its normal "hey, i'm the
last fella here, so i'll clean up the empty beer cans and
pizza boxess before i go" routine,  by removing python
related commands from the context menu (and gawd know what
else!).

The clue that could solve this whole mystery would be specific
information about these "strange errors"...

    (1) Were these python exception messages?
    
    (2) Were they Windows error messages?
    
    (3) Perhaps the flux capacitor failed to produce the
    expected 1.21 GigaWatts? 
    
    Great Scott!!!

With such limited information, all we can do is guess here.
But in my experience, with Python on windoze at least, the
installers can be, as you said, flaky. Especially when you
have multiple versions on the same machine and you forget to
select the little "Make-This-My-Default-Python" box. But of
course, that won't help when you do the uninstall later,
because there's no "Use-VersionXY-As-My-Default-Python" for
the uninstaller. It's a one-way street with no U-Turns
allowed.