## Summary The regex module interprets \w as matching more characters than it seems like it should (certainly more than CPython does). ## Expected ``` import re assert not re.match(r"\w", "\u0345"), r"\w should not match U+0345 (category Mn)" ``` This assertion should pass, but instead it fails. ## Python Documentation https://docs.python.org/3/library/re.html This says that it should match anything for which isalnum() is true. This turns out to be also an area where RustPython and CPython disagree. `"\u0345".isalnum()` returns False on CPython and True on RustPython.