How to check whether a directory is a sub directory of another directory

Python 3’s pathlib module makes this straightforward with its Path.parents attribute. For example:

from pathlib import Path

root = Path('/path/to/root')
child = root / 'some"https://stackoverflow.com/"child"https://stackoverflow.com/"dir'
other = Path('/some/other/path')

Then:

>>> root in child.parents
True
>>> other in child.parents
False