I need to know the ID (or name) of vertices of a polyline (or polygon) to build someting like this image.

[![enter image description here](https://i.stack.imgur.com/A1kKY.png)](https://i.stack.imgur.com/A1kKY.png)

As the tread below I already used @geometry\_point\_num command to have vertex's ID but it return only the number of the vertex on screen and that's not useful for me because I have some km long polyline.

[How to get or assign vertex id to polygon vertices and use these as vertex label using pyqgis?](https://gis.stackexchange.com/questions/215990/how-to-get-or-assign-vertex-id-to-polygon-vertices-and-use-these-as-vertex-label/328386)

That's no good because I need to take absolute ID of vertex like I can show on vertex editing

[![enter image description here](https://i.stack.imgur.com/EkMtD.png)](https://i.stack.imgur.com/EkMtD.png)

In that way I can extract as label text the angle value of the id vertex.

For have the angle value I use something like that:

[![enter image description here](https://i.stack.imgur.com/vEKW0.png)](https://i.stack.imgur.com/vEKW0.png)

I suppose that using the function editor I can get it but I don't know Python and QGIS library.

I also considered to extract the vertex points or subdivide my polyline to lines but that's not useful for my scope.