gh-90568: Fix exception type for \N with a named sequence in RE (GH-91665)

re.error is now raised instead of TypeError.

Author: serhiy-storchaka

Lib/re/_parser.py

@@ -333,7 +333,7 @@ def _class_escape(source, escape):
             charname = source.getuntil('}', 'character name')
             try:
                 c = ord(unicodedata.lookup(charname))
-            except KeyError:
+            except (KeyError, TypeError):
                 raise source.error("undefined character name %r" % charname,
                                    len(charname) + len(r'\N{}')) from None
             return LITERAL, c
@@ -393,7 +393,7 @@ def _escape(source, escape, state):
             charname = source.getuntil('}', 'character name')
             try:
                 c = ord(unicodedata.lookup(charname))
-            except KeyError:
+            except (KeyError, TypeError):
                 raise source.error("undefined character name %r" % charname,
                                    len(charname) + len(r'\N{}')) from None
             return LITERAL, c

Lib/test/test_re.py

@@ -772,6 +772,10 @@ def test_named_unicode_escapes(self):
                                "undefined character name 'SPAM'", 0)
         self.checkPatternError(r'[\N{SPAM}]',
                                "undefined character name 'SPAM'", 1)
+        self.checkPatternError(r'\N{KEYCAP NUMBER SIGN}',
+                            "undefined character name 'KEYCAP NUMBER SIGN'", 0)
+        self.checkPatternError(r'[\N{KEYCAP NUMBER SIGN}]',
+                            "undefined character name 'KEYCAP NUMBER SIGN'", 1)
         self.checkPatternError(br'\N{LESS-THAN SIGN}', r'bad escape \N', 0)
         self.checkPatternError(br'[\N{LESS-THAN SIGN}]', r'bad escape \N', 1)
 

Misc/NEWS.d/next/Library/2022-04-18-16-31-33.gh-issue-90568.9kiU7o.rst

@@ -0,0 +1,3 @@
+Parsing ``\N`` escapes of Unicode Named Character Sequences in a
+:mod:`regular expression <re>` raises now :exc:`re.error` instead of
+``TypeError``.