<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def package_files(directory):
 """Get list of data files to add to the package."""

    paths = []
    for (path, _, file_names) in walk(directory):
        for filename in file_names:
            paths.append(join('..', path, filename))
    return paths