import bpy
from bpy.app.handlers import persistent
import shutil

blender_bin = shutil.which("blender")
if blender_bin:
    print("Found:", blender_bin)
    bpy.app.binary_path = blender_bin
else:
    print("Unable to find blender!")

@persistent
def load_handler(dummy):
    print("Load Handler", bpy.data.filepath)

bpy.app.handlers.load_post(load_handler)