# Bug report ### Bug description: ```python >>> import ntpath >>> ntpath.commonpath(None) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<frozen ntpath>", line 826, in commonpath ValueError: commonpath() arg is an empty sequence ``` Expected: `TypeError: 'NoneType' object is not iterable` like for `posixpath.commonpath`. ### CPython versions tested on: CPython main branch ### Operating systems tested on: macOS <!-- gh-linked-prs --> ### Linked PRs * gh-117336 <!-- /gh-linked-prs -->