Remap & Remove Duplicate Materials + Textures in Blender

remove_dupes.py

import bpy

# credit to https://blender.stackexchange.com/questions/75790/how-to-merge-around-300-duplicate-materials/229803#229803

# remove duplicate materials
def remove_duped_materials():
    mats = bpy.data.materials
    for mat in mats:
        (original, _, ext) = mat.name.rpartition(".")
        
        if ext.isnumeric() and mats.find(original) != -1:
            print("%s -> %s" %(mat.name, original))
            
            mat.user_remap(mats[original])
            mats.remove(mat)

# remove duplicate textures
def remove_duped_textures():
    mats = bpy.data.materials
    for mat in mats:
        if mat.node_tree:
            for n in mat.node_tree.nodes:
                if n.type == 'TEX_IMAGE':
                    if n.image is None:
                        print(mat.name,'has an image node with no image')
                    elif n.image.name[-3:].isdigit():
                        name = n.image.name[:-4]
                        exists = False
                        for img in bpy.data.images:
                            if img.name in name:
                                exists = True
                        if exists:
                            old_name = n.image.name
                            n.image = bpy.data.images[name]
                            print("%s -> %s" %(old_name, n.image.name))
                        else:
                            n.image.name = name

remove_duped_materials()
remove_duped_textures()