Update/overwrite an existing mesh within a collection Python Blender

Question

I have made the following python script which contains one function, this function creates one simple mesh.

import bpy
import mathutils
from itertools import repeat


def add_single_brick(brick_width, brick_length, brick_height):


    mesh_name = "brick" 
    collection_name = bpy.data.collections.new("BrickCollection")
    bpy.context.scene.collection.children.link(collection_name)

    vertices_brick = [  (0,0,0),
                    (0,brick_width,0),
                    (brick_length,brick_width,0),
                    (brick_length,0,0),
                    
                    (0,0,brick_height),
                    (0,brick_width,brick_height),
                    (brick_length,brick_width,brick_height),
                    (brick_length,0,brick_height)
                    ]

    edges = []

    faces = [(0,1,2,3),
         (4,5,6,7),
         (0,4,5,1), 
         (1,5,6,2),
         (2,6,7,3),
         (3,7,4,0)
         ]


    new_mesh = bpy.data.meshes.new('brick_mesh')
    new_mesh.from_pydata(vertices_brick, edges, faces)
    new_mesh.update()


    # make object from mesh
    new_object = bpy.data.objects.new(mesh_name, new_mesh)
    collection_name.objects.link(new_object) 


brick_length = 0.21
brick_width = 0.1
brick_height = 0.05    

add_single_brick(brick_width=brick_width, brick_length=brick_length, brick_height=brick_height)

I call the function at the end of the script to create the mesh within a collection I called 'BrickCollection'

The mesh is in this collection:

When I run the script again with other variables in the parameters, I want the script to update the existing mesh and not make a new mesh.

I found this post 3: When to use bmesh.update_edit_mesh and when Mesh.update? as in which I understand I should start using the bmesh module

I also found this post

I am getting quite confused, now I have two simple questions:

• Is there any simple python example of mesh being overwritten within a collection when running the python script again with different parameters?
• Does the bmesh module also work with modifiers?

Answer 1

I solved it by making a function which checks if the collection already exists, if it exists it removes the content of the collection before calling the function which makes creates the mesh.

def remove_brick_collection():

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

    if (bool(bpy.data.collections.get(name_collection))) == True:
  
        collection = bpy.data.collections.get(name_collection)
        bpy.data.collections.remove(collection)
    
    else:
        print ("no collection found")

at the end of the script:

remove_brick_collection()
add_single_brick(brick_width=1, brick_length=2, brick_height=3)