code: def package_data(pkg, root_list):
      
      data = []
      for root in root_list:
          for dirname, _, files in os.walk(os.path.join(pkg, root)):
              for fname in files:
                  data.append(os.path.relpath(os.path.join(dirname, fname), pkg))
  
      return {pkg: data}
docs: Generic function to find package_data for `pkg` under `root`.