Saving a rendered image with a transparent background thanks to a Python script in Blender 2.8

Question

In my Blender script, I want to save a rendered image with bpy.ops.render.render(write_still=True). This rendered image is supposed to have a transparent background I try to set with scene.render.film_transparent=True, but it's desesperately black...

Any idea about what I could be missing?

Answer 1

Works much better when color mode is set to "RGBA" instead of "RGB"...