import bpy
import random

for i in range(0,21):
    rand_rot_x = random.uniform (-.05,.05)
    rand_rot_z = random.uniform (-.02,.02)
    bpy.ops.mesh.primitive_cube_add(size=1, enter_editmode=False, align='WORLD', location=(i/6.7, 0, .75), scale=(.15, .03, 1.5), rotation=(rand_rot_x,0,rand_rot_z))

#rename first cube to 000
no=1
for obj in bpy.context.scene.objects:
    if obj.type == 'MESH' and obj.name.endswith("ube"):
        obj.name = "Fence0"
    else:
        obj.name = "Fence%d" %no
        no += 1