Blender material change test

change.py

import bpy


def replace_material(obj, obj_data, mat_src, mat_dst):
    """
    replace a material in blender.
    """
    print("ob is", obj)
    for i in range(len(obj_data.materials)):
        # test if the old material is in the slot and replace it
        if obj_data.materials[i] == mat_src:
            print("match found", obj.data.materials[i])
            obj_data.materials[i] = mat_dst

def main():
    # get a list of objects selected
    selected = bpy.context.selected_objects
    active = bpy.context.active_object
    currentmat = active.active_material

    # mat_src = bpy.data.materials['Plaster - Teal']
    mat_src = currentmat
    mat_dst = bpy.data.materials['Glass']

    for obj in selected:
        obj_data = obj.data
        if obj_data and hasattr(obj_data, "materials"):
            replace_material(obj, obj_data, mat_src, mat_dst)


main()