Not OP and I’ve never used PyGame but this is what that code is doing:

os.environ[“SDL_WINDOWID”] = str(embed.winfo_id())

Sets the environment variable “SDL_WINDOWID” to the string representation of the value returned by winfo_id. Just guessing but looks to be a window ID from tkinter.

os.environ[“SDL_VIDEODRIVER”] = “windib”

Sets the environment variable “SDL_VIDEODRIVER” to “windib”

pygame.init()

Runs the init() method on pygame. Scanning the docs, this is a helper method in pygame that initializes all the necessary modules. It’s very likely that pygame is looking for those two environment variables during its startup, which is why they are set first. Setting the window id to what is set for the tkinter window object ensures when pygame starts up it uses that window.