Hi, I'm learning to program on the python api.

I'm making a generation extension. At this moment I make a duplicate of the selected shape, i make some stuff to the copy and then I return the new shape or path.

Would it be possible to return several shapes?

VERSION of inkscape: Inkscape 1.3.2 (091e20e, 2023-11-25, custom)

I would say if you need to use the contents of the existing svg, then it's better to make an effect extension instead of a generate extension.

Generate extension are not used that much, 

A basic EffectExtension can do everything you want.

The difference is that the Generate extension returns an svg fragment instead of the entire svg - which for most cases is more difficult to work with. (In my opinion)

import inkex
from inkex import Layer

from random import randint

def duplicate_and_change_style(self, selection_list, to_new_layer=False):

    duplicate_list = []

    for selected in selection_list:
        # Duplicated the selected item on canvas
        duplicate = selected.duplicate()
        # Lets change some styles
        random_rgb = f'rgb({randint(0, 255)}, {randint(0, 255)}, {randint(0, 255)})'
        duplicate.style['fill'] = random_rgb
        duplicate_list.append(duplicate)

    # Should we move the duplicates to a new layer ?
    if to_new_layer:
        new_layer = Layer()
        for element in duplicate_list:
            # elements can only be in one place at once
            # so append moves them
            new_layer.append(element)
        # Make the new layer a sublayer of current layer
        self.svg.get_current_layer().append(new_layer)

class DuplicateShapesTest(inkex.EffectExtension):

    def add_arguments(self, pars):
        pass
    
    def effect(self):

        # Create a filtered selection list
        selection_list = self.svg.selected.filter((inkex.ShapeElement, inkex.PathElement))

        # Exit if the selection list does not contain anything
        if len(selection_list) < 1:
            inkex.errormsg('Please select at least one object')
            return

        # Print the selection list in msgbox
        for selection in selection_list:
            inkex.errormsg(f'{selection} {selection.get_id()}')

        # Run the duplicate function
        # Change to_new_layer to True or False however you want.
        duplicate_and_change_style(self, selection_list, to_new_layer=True)


if __name__ == '__main__':
    DuplicateShapesTest().run()

Thank you ¡very much! @inklinea This was helpful indeed.