Blender script to load in an FBX then decimate all meshes it contains

decimate.py

import bpy
import sys
import time

argv = sys.argv
argv = argv[argv.index("--") + 1:]  # get all args after "--"

if len(argv) < 2:
  print("Give arguments -- fbx_file decimate_ratio")

startTime = time.time()

def log(msg):
  s = round(time.time() - startTime, 2)
  print("{}s {}".format(s, msg))

fbxFile = argv[0]
decimateRatio = float(argv[1])

# Clear Blender scene
for obj in bpy.data.objects:
  bpy.data.objects.remove(obj, do_unlink=True)
for mesh in bpy.data.meshes:
  bpy.data.meshes.remove(mesh)

s = time.time()
bpy.ops.import_scene.fbx(filepath=fbxFile)
log("Loaded")

modifierName='DecimateMod'

objectList=bpy.data.objects
meshes = []
for obj in objectList:
  if(obj.type == "MESH"):
    meshes.append(obj)

log("{} meshes".format(len(meshes)))

for i, obj in enumerate(meshes):
  bpy.context.scene.objects.active = obj
  log("{}/{} meshes, name: {}".format(i, len(meshes), obj.name))
  log("{} has {} verts, {} edges, {} polys".format(obj.name, len(obj.data.vertices), len(obj.data.edges), len(obj.data.polygons)))
  modifier = obj.modifiers.new(modifierName,'DECIMATE')
  modifier.ratio = decimateRatio
  modifier.use_collapse_triangulate = True
  bpy.ops.object.modifier_apply(apply_as='DATA', modifier=modifierName)
  log("{} has {} verts, {} edges, {} polys after decimation".format(obj.name, len(obj.data.vertices), len(obj.data.edges), len(obj.data.polygons)))

Sankyu very much