RustPython · youknowone · Apr 19, 2026 · Apr 18, 2026
diff --git a/Lib/test/test_str.py b/Lib/test/test_str.py
@@ -792,7 +792,6 @@ def test_isdecimal(self):
         for ch in ['\U0001D7F6', '\U00011066', '\U000104A0']:
             self.assertTrue(ch.isdecimal(), '{!a} is decimal.'.format(ch))
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: False != True
     def test_isdigit(self):
         super().test_isdigit()
         self.checkequalnofix(True, '\u2460', 'isdigit')

diff --git a/crates/sre_engine/src/string.rs b/crates/sre_engine/src/string.rs
@@ -1,4 +1,4 @@
-use icu_properties::props::{CanonicalCombiningClass, EnumeratedProperty};
+use icu_properties::props::{EnumeratedProperty, GeneralCategory, GeneralCategoryGroup};
 use rustpython_wtf8::Wtf8;
 
 #[derive(Debug, Clone, Copy)]
@@ -444,9 +444,10 @@ pub(crate) const fn is_uni_linebreak(ch: u32) -> bool {
 pub(crate) fn is_uni_alnum(ch: u32) -> bool {
     // TODO: check with cpython
     char::try_from(ch)
-        .map(|x| {
-            x.is_alphanumeric()
-                && CanonicalCombiningClass::for_char(x) == CanonicalCombiningClass::NotReordered
+        .map(|c| {
+            GeneralCategoryGroup::Letter
+                .union(GeneralCategoryGroup::Number)
+                .contains(GeneralCategory::for_char(c))
         })
         .unwrap_or(false)
 }

diff --git a/crates/vm/src/builtins/str.rs b/crates/vm/src/builtins/str.rs
@@ -45,8 +45,8 @@ use rustpython_common::{
 };
 
 use icu_properties::props::{
-    BidiClass, BinaryProperty, CanonicalCombiningClass, EnumeratedProperty, GeneralCategory,
-    XidContinue, XidStart,
+    BidiClass, BinaryProperty, EnumeratedProperty, GeneralCategory, GeneralCategoryGroup,
+    NumericType, XidContinue, XidStart,
 };
 use unicode_casing::CharExt;
 
@@ -949,23 +949,30 @@ impl PyStr {
     fn isalnum(&self) -> bool {
         !self.data.is_empty()
             && self.char_all(|c| {
-                c.is_alphanumeric()
-                    && CanonicalCombiningClass::for_char(c) == CanonicalCombiningClass::NotReordered
+                GeneralCategoryGroup::Letter
+                    .union(GeneralCategoryGroup::Number)
+                    .contains(GeneralCategory::for_char(c))
             })
     }
 
     #[pymethod]
     fn isnumeric(&self) -> bool {
-        !self.data.is_empty() && self.char_all(char::is_numeric)
+        !self.data.is_empty()
+            && self.char_all(|c| {
+                [
+                    NumericType::Decimal,
+                    NumericType::Digit,
+                    NumericType::Numeric,
+                ]
+                .contains(&NumericType::for_char(c))
+            })
     }
 
     #[pymethod]
     fn isdigit(&self) -> bool {
-        // python's isdigit also checks if exponents are digits, these are the unicode codepoints for exponents
         !self.data.is_empty()
             && self.char_all(|c| {
-                c.is_ascii_digit()
-                    || matches!(c, '⁰' | '¹' | '²' | '³' | '⁴' | '⁵' | '⁶' | '⁷' | '⁸' | '⁹')
+                [NumericType::Digit, NumericType::Decimal].contains(&NumericType::for_char(c))
             })
     }
 
@@ -1064,7 +1071,9 @@ impl PyStr {
 
     #[pymethod]
     fn isalpha(&self) -> bool {
-        !self.data.is_empty() && self.char_all(char::is_alphabetic)
+        !self.data.is_empty()
+            && self
+                .char_all(|c| GeneralCategoryGroup::Letter.contains(GeneralCategory::for_char(c)))
     }
 
     #[pymethod]

diff --git a/extra_tests/snippets/builtin_str.py b/extra_tests/snippets/builtin_str.py
@@ -72,16 +72,29 @@
 assert "\u1c89".istitle()
 # assert "Ǳ".title() == "ǲ"
 assert a.isalpha()
+assert not "\u093f".isalpha()
 
 # Combining characters differ slightly between Rust and Python
 assert "\u006e".isalnum()
 assert not "\u0303".isalnum()
 assert not "\u006e\u0303".isalnum()
 assert "\u00f1".isalnum()
 assert not "\u0345".isalnum()
+assert not "\u093f".isalnum()
 for raw in range(0x0363, 0x036F):
     assert not chr(raw).isalnum()
 
+# isdigit is true for exponents
+assert "⁰".isdigit()
+assert "⁰".isnumeric()
+assert not "½".isdigit()
+assert "½".isnumeric()
+assert not "Ⅻ".isdigit()
+assert "Ⅻ".isnumeric()
+
+# isnumeric is broader than Rust's
+assert "\u3405".isnumeric()
+
 s = "1 2 3"
 assert s.split(" ", 1) == ["1", "2 3"]
 assert s.rsplit(" ", 1) == ["1 2", "3"]