Terry, the unittest and regrtest command lines are *built* for TDD - you
rely on test discovery and selection to run the appropriate tests for what
you're working on.

However, the point about F5 in IDLE is well made, and a reasonable
rationale for ensuring at least the IDLE implementation files support
running their tests that way.

While it doesn't need to be extensive, it would be good to capture some of
these points in a Idle/idle_tests/README file.