Emacs Code Browser (Navegador de Código de Emacs, on spanish).
We present a configuration of windows in which will include a
browser of files and directories, a browser of objects within
our code and a history in addition to the window of our code.
The diminish mode is activated, which helps us to keep the modeline clean.
As we see, in the modeline the modes that are activated are shown, and every time
we have more activated minor-modes, which add small functionalities to Emacs.
In this case, there are many modes, that if they do not appear, nothing happens.
So we hide some, like undo-tree that will always be activated.
When you open a python file, emacs guesses the indentation offset (number of spaces to indent) based on that file style.
When you create a file (the case you describe), emacs cannot guess (file is empty) so it uses your default (4) and notifies the user.
In other words: tt is a harmless warning; if you find this is a bug please report it as such.
If you don't like emacs guessing the offset, customize the variable python-indent-guess-indent-offset to nil,
and then emacs will use always your default (very unsafe in python,
where indentation has meaning and you could be editing a file created by somebody else with other defaults).
Active auto-revert-mode that automatically reloads modified files out of Emacs.
It is very useful to see logs (like auto-revert-tail-mode) among many other cases.
