Blender Sapling OBJ Exporter

import bpy
import os

basedir = bpy.path.abspath('//shadefoot/story_mode/ch1/trees/maple/')

bpy.ops.object.select_all(action='DESELECT')

scene = bpy.context.scene

for obj in scene.objects:
    scene.objects.active = obj
    
    obj.select = True
    
    for child in obj.children:
        child.select = True
    
    if obj.type == 'CURVE':
        bpy.ops.export_scene.obj(filepath = os.path.join(basedir, obj.name + ".obj"), use_selection = True)
    
    
    for child in obj.children:
        child.select = False
    obj.select = False