unitypackage unpacker

unpack.py

import argparse
import tarfile
import os
import io

class UnityAsset:
    pass

parser = argparse.ArgumentParser(description='Unpack a .unitypackage')
parser.add_argument('INPUT_PACKAGE', help='path to a .unitypackage file')
parser.add_argument('-o', '--output', help='output directory (defaults to current directory)')
args = parser.parse_args()
print('.unitypackage file = ' + args.INPUT_PACKAGE)
if (args.output):
    output_directory = args.output
else:
    output_directory = '.'

paths = {}

with tarfile.open(args.INPUT_PACKAGE, 'r|gz') as archive:
    for entry in archive.getmembers():
        guid = os.path.dirname(entry.name)
        if (guid not in paths):
            paths[guid] = UnityAsset()
        if (entry.isfile() and os.path.basename(entry.name) == 'pathname'):
            paths[guid].pathname_file = entry
        elif (os.path.basename(entry.name) == 'asset.meta'):
            paths[guid].meta_file = entry
        elif (os.path.basename(entry.name) == 'asset'):
            paths[guid].asset_file = entry

for entry in paths:
    if (hasattr(paths[entry], 'pathname_file')):
        pathname = output_directory
        pathname_file = paths[entry].pathname_file
        with tarfile.open(args.INPUT_PACKAGE, 'r|gz') as archive:
            with archive.extractfile(pathname_file) as pathfile:
                with io.TextIOWrapper(io.BytesIO(pathfile.read())) as path:
                    pathname = os.path.join(output_directory, path.readline().strip())
                    os.makedirs(os.path.dirname(pathname), exist_ok=True)
        if (hasattr(paths[entry], 'meta_file')):
            print(pathname + '.meta')
            with tarfile.open(args.INPUT_PACKAGE, 'r|gz') as archive:
                with archive.extractfile(paths[entry].meta_file) as meta_file:
                    with open(pathname + '.meta', 'wb') as output_file:
                        output_file.write(meta_file.read())
        if (hasattr(paths[entry], 'asset_file')):
            print(pathname)
            with tarfile.open(args.INPUT_PACKAGE, 'r|gz') as archive:
                with archive.extractfile(paths[entry].asset_file) as asset_file:
                    with open(pathname, 'wb') as output_file:
                        output_file.write(asset_file.read())

extract file names

output files