Ever been irritated at the internal names of your xcassets images? Use caution, though, this has only been tested with standard (1x), 2x, 3x image sets.

rename_asset_images.py

import os
import sys
import json

def rename_asset_images(imageset_path):
    if not imageset_path.endswith('.imageset'):
        print(f"Skipping {imageset_path}: not an .imageset folder")
        return

    base_name = os.path.splitext(os.path.basename(imageset_path))[0]
    contents_path = os.path.join(imageset_path, 'Contents.json')

    if not os.path.exists(contents_path):
        print(f"Error: {contents_path} not found.")
        return

    try:
        with open(contents_path, 'r', encoding='utf-8') as f:
            contents = json.load(f)
    except json.JSONDecodeError as e:
        print(f"Error parsing JSON in {contents_path}: {e}")
        return

    updated = False
    for image in contents.get('images', []):
        old_filename = image.get('filename')
        scale = image.get('scale')

        if not old_filename or not scale:
            continue

        ext = os.path.splitext(old_filename)[1]
        new_filename = f"{base_name}@{scale}{ext}" if scale != '1x' else f"{base_name}{ext}"

        old_path = os.path.join(imageset_path, old_filename)
        new_path = os.path.join(imageset_path, new_filename)

        if os.path.exists(old_path) and old_filename != new_filename:
            os.rename(old_path, new_path)
            image['filename'] = new_filename
            print(f"[{base_name}] Renamed: {old_filename} → {new_filename}")
            updated = True
        elif not os.path.exists(old_path):
            print(f"[{base_name}] Warning: {old_filename} not found")

    if updated:
        with open(contents_path, 'w', encoding='utf-8') as f:
            json.dump(contents, f, indent=2)
            print(f"[{base_name}] Contents.json updated")
    else:
        print(f"[{base_name}] No changes made")

# --- CLI usage ---
if __name__ == '__main__':
    if len(sys.argv) < 2:
        print("Usage: python rename_asset_images.py <*.imageset> [...]")
        sys.exit(1)

    for path in sys.argv[1:]:
        rename_asset_images(path)