Final code for a Beginner Blender Python Tutorial about refactoring and animating (link to tutorial: https://youtu.be/tC_Bu-VO8p0)

refactor_and_animate.py

# give Python access to Blender's functionality
import bpy

# extend Python's math functionality
import math

# extend Python functionality to generate random numbers
import random


def create_mesh():
    # add a cube mesh into the scene
    bpy.ops.mesh.primitive_cube_add()

    # get a reference to the currently active object
    obj = bpy.context.active_object

    # scale the cube mesh
    obj.scale.x = obj.scale.x * 0.5
    obj.scale.y = obj.scale.y * 2
    obj.scale.z = obj.scale.z * 0.1

    # apply random rotation
    random_rotation = random.uniform(0, 360)
    obj.rotation_euler.z = math.radians(random_rotation)

    # apply the scale
    bpy.ops.object.transform_apply()

    return obj


def update_obj_transform(obj, current_angle):
    # update the location of the object on the Z axis
    obj.location.z += obj.dimensions.z

    # update the rotation
    obj.rotation_euler.z = math.radians(current_angle)


def animate_rotation(obj, current_frame, rotation_frame_count):
    # remove the animation data from the duplicated object
    obj.animation_data_clear()

    # insert key frame
    obj.keyframe_insert("rotation_euler", frame=current_frame)

    # rotate object
    obj.rotation_euler.z += math.radians(360)

    # calculate the end frame
    frame = current_frame + rotation_frame_count

    # insert key frame
    obj.keyframe_insert("rotation_euler", frame=frame)


def create_next_layer(current_angle, current_frame, rotation_frame_count):
    # duplicate the mesh
    bpy.ops.object.duplicate(linked=True)

    # get a reference to the currently active object
    obj = bpy.context.active_object

    update_obj_transform(obj, current_angle)

    animate_rotation(obj, current_frame, rotation_frame_count)


def main():
    obj = create_mesh()

    # create variables for stacking and rotating
    angle_step = 3
    current_angle = angle_step

    # create variables for animating the rotation
    current_frame = 1
    frame_step = 1
    rotation_frame_count = 90

    # animate the original mesh
    animate_rotation(obj, current_frame, rotation_frame_count)

    # stack and rotate the mesh
    while current_angle <= 360:

        create_next_layer(current_angle, current_frame, rotation_frame_count)

        # update the angle for the next iteration
        current_angle += angle_step

        # update the current_frame
        current_frame += frame_step

    # update the end frame for the whole animation
    bpy.context.scene.frame_end = current_frame + rotation_frame_count


main()