Animate Lego sets in Blender

brickanimator.py

import bpy
from mathutils import Vector

# Edit these:
offset = 1 # Offset is the interval between each brick appearance
startFrame = 0 # Start Frame is the frame that the brick animation starts on

# Variables
frameNum = startFrame
selectedBricks = bpy.context.selected_objects

# Bricks with lower z value get called first
sortedBricks = sorted(selectedBricks, key=lambda x: x.location[2])

# Loop on all selected bricks
for brick in sortedBricks:
    
    # Set new scale to brick
    brick.scale = Vector((0, 0, 0))
    # Add keyframe
    brick.keyframe_insert(data_path="scale", frame=frameNum, index=-1)
    
    # Jump one frame
    newFrame = frameNum + 1
    
    # Set new scale to brick
    brick.scale = Vector((1.0, 1.0, 1.0))
    # Add keyframe
    brick.keyframe_insert(data_path="scale", frame=newFrame, index=-1)
    
    # Go to next offset
    frameNum += offset
    
# Go to start frame
bpy.context.scene.frame_set(startFrame)