Window.unminimize
void unminimize()Asks to unminimize the specified window.
Note that you shouldn’t assume the window is definitely unminimized afterward, because the windowing system might not support this functionality; other entities (e.g. the user or the window manager) could minimize it again, or there may not be a window manager in which case minimization isn’t possible, etc.
You can track result of this operation via the [gdk.toplevel.Toplevel.state] property.