For example, sort ```python import re import sre_constants import sre_parse ``` and `sre_parse` will be placed in a new section, which is a regression from isort 4.3.21, where `sre_parse` was correctly treated as a stdlib module. (and thanks for shipping isort 5! The new API is great for [my `shed` project](https://pypi.org/project/shed/), and as a user I also really like the profile system :smile:)