sqlite3: add Connection exception attributes and fix autocommit ValueError (#8533)

Add DB-API 2.0 optional extension: expose exception classes as attributes
on Connection objects (Warning, Error, InterfaceError, DatabaseError,
DataError, OperationalError, IntegrityError, InternalError,
ProgrammingError, NotSupportedError).

Also fix autocommit validation to raise ValueError (not TypeError) when
an unsupported type is passed.

Assisted-by: GitHub Copilot:claude-sonnet-4-6

Lib/test/test_sqlite3/test_dbapi.py

@@ -364,7 +364,6 @@ class ConnectionTests(unittest.TestCase):
             with self.cx:
                 pass
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_exceptions(self):
         # Optional DB-API extension.
         self.assertEqual(self.cx.Warning, sqlite.Warning)
@@ -401,7 +400,6 @@ class ConnectionTests(unittest.TestCase):
         with self.assertRaises(AttributeError):
             self.cx.in_transaction = True
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_connection_exceptions(self):
         exceptions = [
             "DataError",

Lib/test/test_sqlite3/test_transactions.py

@@ -387,7 +387,6 @@ class AutocommitAttribute(unittest.TestCase):
                     cx.autocommit = mode
                     self.assertEqual(cx.autocommit, mode)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; autocommit validation error messages differ
     def test_autocommit_setget_invalid(self):
         msg = "autocommit must be True, False, or.*LEGACY"
         for mode in "a", 12, (), None:

crates/stdlib/src/_sqlite3.rs

@@ -322,7 +322,7 @@ mod _sqlite3 {
                     )))
                 }
             } else {
-                Err(vm.new_type_error(format!(
+                Err(vm.new_value_error(format!(
                     "autocommit must be True, False, or sqlite3.LEGACY_TRANSACTION_CONTROL, not {}",
                     obj.class().name()
                 )))
@@ -1645,6 +1645,47 @@ mod _sqlite3 {
         fn total_changes(&self, vm: &VirtualMachine) -> PyResult<c_int> {
             self._db_lock(vm).map(|x| x.total_changes())
         }
+
+        #[pygetset(name = "Warning")]
+        fn exc_warning(&self) -> PyTypeRef {
+            warning_type().to_owned()
+        }
+        #[pygetset(name = "Error")]
+        fn exc_error(&self) -> PyTypeRef {
+            error_type().to_owned()
+        }
+        #[pygetset(name = "InterfaceError")]
+        fn exc_interface_error(&self) -> PyTypeRef {
+            interface_error_type().to_owned()
+        }
+        #[pygetset(name = "DatabaseError")]
+        fn exc_database_error(&self) -> PyTypeRef {
+            database_error_type().to_owned()
+        }
+        #[pygetset(name = "DataError")]
+        fn exc_data_error(&self) -> PyTypeRef {
+            data_error_type().to_owned()
+        }
+        #[pygetset(name = "OperationalError")]
+        fn exc_operational_error(&self) -> PyTypeRef {
+            operational_error_type().to_owned()
+        }
+        #[pygetset(name = "IntegrityError")]
+        fn exc_integrity_error(&self) -> PyTypeRef {
+            integrity_error_type().to_owned()
+        }
+        #[pygetset(name = "InternalError")]
+        fn exc_internal_error(&self) -> PyTypeRef {
+            internal_error_type().to_owned()
+        }
+        #[pygetset(name = "ProgrammingError")]
+        fn exc_programming_error(&self) -> PyTypeRef {
+            programming_error_type().to_owned()
+        }
+        #[pygetset(name = "NotSupportedError")]
+        fn exc_not_supported_error(&self) -> PyTypeRef {
+            not_supported_error_type().to_owned()
+        }
     }
 
     #[pyattr]