Initial

Author: StanFromIreland

Lib/_pydatetime.py

@@ -1051,8 +1051,8 @@ def fromordinal(cls, n):
     @classmethod
     def fromisoformat(cls, date_string):
         """Construct a date from a string in ISO 8601 format."""
-        if not isinstance(date_string, str):
-            raise TypeError('fromisoformat: argument must be str')
+        if not isinstance(date_string, str) or not date_string.isascii():
+            raise TypeError('fromisoformat: argument must be an ASCII str')
 
         if len(date_string) not in (7, 8, 10):
             raise ValueError(f'Invalid isoformat string: {date_string!r}')

Misc/NEWS.d/next/Library/2025-03-09-10-37-00.gh-issue-89157.qg3r138.rst

@@ -0,0 +1,4 @@
+The pure Python implementation of :func:`datetime.date.fromisoformat`,
+:func:`_pydatetime.date.fromisoformat` now only accepts ASCII strings for
+consistency with the C implementation.
+