When parsing and normalizing a path, pathlib calls sys.intern() on the string parts:

I've never been able to establish that this is a worthwhile thing to do. The implementation seems incomplete, because the path normalization only occurs when a user manually initialises a path object, and not in paths generated from path.iterdir(), path.walk(), etc. Drives/roots/anchors aren't interned despite most likely to be shared.

Previous discussion: #112856 (comment)

Linked PRs

• GH-119518: Stop interning strings in pathlib #123356