This answer
bpy.app.handlers
CLI tool
-b
blender -b proj.blend --python-expr "import bpy;print(bpy.context.scene.frame_start, bpy.context.scene.frame_end)"
blender -b project.blend -a
...
Fra:3 Mem:17.40M (0.00M, Peak 23.73M) | Time:00:00.10 | Scene, Part 230-240
Fra:3 Mem:17.37M (0.00M, Peak 23.73M) | Time:00:00.10 | Scene, Part 228-240
Fra:3 Mem:17.35M (0.00M, Peak 23.73M) | Time:00:00.10 | Scene, Part 231-240
...