Did you add the code above to your dotfile, and restart Emacs? Then, what is the value of the post-self-insert-hook while you are woking in some LaTeX buffer?

I have not looked further into the problem, but I guess you can simply define a function (defun nottexmathp () (not (texmathp))) and use it as condition :cond #'nottexmathp.

I am not sure what you are trying to do, but I see a root.mainloop(), so I guess you would want to set compile-command and then use M-x (re)compile (you can prefix it with a universal argument to run the compile buffer in comint-mode, i.e. make it interactive). You can use the following to set the compile command automatically (add-hook 'python-mode-hook (lambda () (setq-local compile-command (format "python %s" buffer-file-name))))

You mean something like xref-find-references? (which probably works best when using a language server via eglot or lsp-mode).

If you'd like to use a debugger, then probably LSP-mode will be easiest to use. Otherwise, indeed, as mentioned by @Ian, go with eglot. Personally, I think the best option for a starter is to use a starter kit like Spacemacs or Doom Emacs, they are great (and can be used with Emacs keybindings, although the experience is better when using vim/evil keybindings).

Not sure what exactly causes this message, but maybe you can try installing elpy via M-x package-list-packages, while making sure that you install from the 'melpa-stable' archive.

I am not sure what is the goal here; or why you could not just use: (let ((a 5)) (format "%d" (transform a))) (you could surround that (transfrom a) with a replacer and/or replace %d with %s if necessary). Could you clear that up? B.t.w. a sexp does not have to start with a ( (see e.g. Parsing Expressions).

And I forgot to mention that I printed out also (buffer-substring (point) (point-max)) and indeed then we can see that point ends up at various places.

Okay, I can reproduce it now indeed. Weird indeed. As the comment before the line-move-1 definition says it is the gut of previous-line, I have tried using previous-line also, then the behavior is even more weird. Also, I have tried (forward -1) in which case the function seems to work correctly. Furthermore, I have used all variants of move-around within test.txt itself, in which case all variants seem to work fine. I have no idea what happens here (you could file a bug and you might get an answer), but at least using (forward-line -1) seems to work correctly.

I can not reporiduce it here using eval-last-sexp. But you can try printing the (buffer-size) additionally... see if that is constant.

Thanks! Indeed, I did not know about the 10 lines 'rule' and the org-babel-min-lines-for-block-output.