20/07/24 15:16:03.14 Y2miOylG.net
>>138
from pathlib import Path
root = Path(r"/dir0")
path = Path(r"/dir0/dir1/dir2/dir3")
root.joinpath(path.relative_to(root).parts[0])
Pathじゃなく文字列が欲しいだけなら
root = '/dir0/dir1'
path = "/dir0/dir1/dir2/dir3"
'/'.join(x for x in path.split('/') if x in root.split('/'))
どっちもスマートとは言い難いが