'1.0', copied from the old code, seems wrong, as it is the Shell top, before the sign-in message, let alone the first prompt. If one hits Enter at the prompt, I would think that the code should be set to '\n'.

I need to add some prints to be sure of what happens in Shell and editor with various inputs.

In the shell, it looks like it will always find the last console tag, which is marked from the beginning to the end of the prompt. For example, in a new shell window, typing >>> def hello( without pressing Enter shows r to be (3.0, 3.4).

I wasn't able to think of a scenario where the prompt would be missing in a real shell, so I'm not sure if the default of 1.0 would ever be used there. However, adding a print(r) and running the testsuite shows that the console tag isn't set for most tests, so it falls back to the default.

Then the shell tests are unrealistic. Of course, with the prompt moved to a sidebar, we should be looking, I believe, for a mark.

Of course, with the prompt moved to a sidebar, we should be looking, I believe, for a mark.

With the shell moved to a sidebar (PR GH-15474), there's still a "console" tag on the newline (\n) before the beginning of the current input block, making code such as this continue to "just work".

While we're refactoring this, I think it's a great opportunity to remove the shell-specific part of this code from the EditorWindow class and into PyShell.