mc_asset_decoder.py

import json
import os
import shutil

# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
# Change this to the version you want to extract the assets from
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
version = "1.12-af"

minecraft_path = os.getenv('APPDATA') + r"\.minecraft\assets"
objects_path = minecraft_path + r"\objects"
indexes_path = minecraft_path + r"\indexes"
version_file = version + ".json"
version_list = os.listdir(indexes_path)


max_modified = 0
for ver in version_list:
	full_path = os.path.join(indexes_path, ver)
	modified = os.path.getmtime(full_path)
	if modified > max_modified:
		max_modified = modified
		latest_modified = ver


if version_file not in version_list:
	raise Exception("The selected version was not found.")
else:
	if version_file is latest_modified:
		pass
		#raise Exception("The selected version was not the latest version played.")
	else:
		indexes = os.path.join(indexes_path, version_file)
		with open(indexes) as f:
			lines = f.readlines()
		file = "".join(lines)
		json = json.loads(file)
		json = json["objects"]

		
if not os.path.exists(version):
	os.makedirs(version)


objects = {}

for i,object in enumerate(json):	
	hash = list(json.values())[i]["hash"]
	objects[object] = hash


count = 0
for object, hash in objects.items():
	count += 1
	print("Processing file {}/{}: {}".format(count, len(objects), object))

	source_file = os.path.join(objects_path, hash[:2], hash)
	destination_file = os.path.join(version, object)
	destination_folder = os.path.dirname(destination_file)
	if not os.path.exists(destination_folder):
		os.makedirs(destination_folder)
	
	shutil.copy(source_file, destination_folder)
	old_filename = os.path.join(destination_folder, hash)
	os.rename(old_filename, destination_file)