Is possible to obligate to play in fullscreen and window?

[stwkun]

The idea is the following. In certain part of the game, the player will play in window and in other part of the game, the player will play in fullscreen.

Are there a code to do that?

And another question. It's possible to block the Window/fullscreen funcion, even if the player press "f" and set up one of them by default without a chance to be modified by the player?

[Ocelot]

It's possible to block the Window/fullscreen funcion

Not completely. You can remove fullscreen button and remove hotkey ( https://www.renpy.org/doc/html/keymap.html ), but dedicated user will just laugh at that.
For example programs like Glide allow to force games to play in window. And it possible to make this window to take up whole screen to be essentially fulscreen.

[stwkun]

Well , thank you for give me a hint of one of my questions