First of all, installing Python on Windows creates a 'Edit with IDLE'
context-menu item whenever you right-click a .py file, which opens IDLE
without a subprocess. The reason for this is that there is still a
problem regarding having several instances of IDLE, each with a
subprocess, open in parallel on Windows. The result is that many users
on Windows are often running IDLE without a subprocess; we can't treat
it as an 'expert' mode.

IMHO if you really feel strongly about this, then the Windows issue must
be resolved, and the 'Edit with IDLE' context-menu item should run IDLE
with a subprocess.


I understand your point that having the shell be restarted every time
helps teach good programming practices. But IDLE is used not only as a
learning environment; it's also a great Python shell for other purposes,
such as testing & debugging or scientific uses. I agree that these are
more advanced uses, so perhaps restarting the shell could be the
default, and the option to not have it restarted available when needed.

Thinking about it, I like the idea of an extension which is disabled by
default. I'll think about it some more, and then perhaps implement it.
Just a thought: It would be important to mention such an extension in a
prominent place in the documentation.