import bpy
import math

# This will remove all the objects.  Did we really need to?
# It's handy if we're going to run this a bunch of times
bpy.ops.object.select_all(action='SELECT') # Default action is TOGGLE
bpy.ops.object.delete()

for stair in range(1, 10):
    center = (0, stair * 2, stair)
    bpy.ops.mesh.primitive_cube_add(location=center)
    new_stair = bpy.context.active_object
    new_stair.scale = (2, 2, 0.5)

for stair in range(1, 10):
    center = (0, -stair * 2, stair)
    bpy.ops.mesh.primitive_cube_add(location=center)
    new_stair = bpy.context.active_object
    new_stair.scale = (2, 2, 0.5)

for stair in range(1, 10):
    center = (0, -(10 - stair) * 2, stair + 9)
    bpy.ops.mesh.primitive_cube_add(location=center)
    new_stair = bpy.context.active_object
    new_stair.scale = (2, 2, 0.5)
    
for stair in range(1, 10):
    center = (0, (10 - stair) * 2, stair + 9)
    bpy.ops.mesh.primitive_cube_add(location=center)
    new_stair = bpy.context.active_object
    new_stair.scale = (2, 2, 0.5)