> I think your suggestions are all good ones, and I have incorporated
> them into the file.
Great :)  You left some commented-out debugging prints.

> (But do note that the departures we are now making from Ned's own
> copy of the tracer code ­— removing the commented-out debugging
> statement, and the long comment, and the inheritance from object —
> might make it harder to bring in changes from his own copy if he
> should ever further improve it.)
I’m not concerned by this.  I’ve been doing merges all the time for more that a year, and having a few diverging lines is not a big deal.

> I have tried to write the comments to be more informative, while also
> addressing your own ideas; let me know if you like the result!
I do!

> Oh: and, I am continuing to use this new file in my own work on the
> Python core, and it has been working fine — so no problems with the
> actual code have developed over these first 3+ months of use.
This is a good thing to know.

I’ll let Brett take over now.