When running a local unittest as a module (for example, `python -m unittest ./tests/*.py`), the command fails with a ValueError. However, if we remove the local directory definition, and call it as `python -m unittest tests/*.py`, it runs without issue. A GitHub pull request with a pull request will be sent promptly.

For reference, this is the error request: ``` python3 -m unittest ./tests/*.py Traceback (most recent call last): File "/usr/lib64/python3.10/runpy.py", line 196, in _run_module_as_main return _run_code(code, main_globals, None, File "/usr/lib64/python3.10/runpy.py", line 86, in _run_code exec(code, run_globals) File "/usr/lib64/python3.10/unittest/__main__.py", line 18, in <module> main(module=None) File "/usr/lib64/python3.10/unittest/main.py", line 100, in __init__ self.parseArgs(argv) File "/usr/lib64/python3.10/unittest/main.py", line 147, in parseArgs self.createTests() File "/usr/lib64/python3.10/unittest/main.py", line 158, in createTests self.test = self.testLoader.loadTestsFromNames(self.testNames, File "/usr/lib64/python3.10/unittest/loader.py", line 220, in loadTestsFromNames suites = [self.loadTestsFromName(name, module) for name in names] File "/usr/lib64/python3.10/unittest/loader.py", line 220, in <listcomp> suites = [self.loadTestsFromName(name, module) for name in names] File "/usr/lib64/python3.10/unittest/loader.py", line 154, in loadTestsFromName module = __import__(module_name) ValueError: Empty module name ``` The issue stems with having "." as its own value in the parts list of `unittest/loader.py`. https://github.com/python/cpython/blob/main/Lib/unittest/loader.py#L125

 New changeset a0db11b10fca0fee6bb2b8d6277e266bad8c0fdb by Bader Zaidan in branch 'main': bpo-46421: Fix unittest filename evaluation when called as a module (GH-30654) https://github.com/python/cpython/commit/a0db11b10fca0fee6bb2b8d6277e266bad8c0fdb 

 New changeset 0b5f99ad1af0892a2d6043abd8aeb10d685d3844 by Miss Islington (bot) in branch '3.10': bpo-46421: Fix unittest filename evaluation when called as a module (GH-30654) https://github.com/python/cpython/commit/0b5f99ad1af0892a2d6043abd8aeb10d685d3844 

 New changeset 1cab44d8650ae3eece90b04fca373908205e7ee0 by Miss Islington (bot) in branch '3.9': [3.9] bpo-46421: Fix unittest filename evaluation when called as a module (GH-30654) (GH-31970) https://github.com/python/cpython/commit/1cab44d8650ae3eece90b04fca373908205e7ee0