code: def copytree_hardlink(source, dest):
      
      copy2 = shutil.copy2
      try:
          shutil.copy2 = os.link
          shutil.copytree(source, dest)
      finally:
          shutil.copy2 = copy2
docs: Recursively copy a directory ala shutils.copytree, but hardlink files
      instead of copying. Available on UNIX systems only.