gh-126947: Typechecking for _pydatetime.timedelta.__new__ arguments

Lib/_pydatetime.py

@@ -651,7 +651,19 @@ def __new__(cls, days=0, seconds=0, microseconds=0,
         # guide the C implementation; it's way more convoluted than speed-
         # ignoring auto-overflow-to-long idiomatic Python could be.
 
-        # XXX Check that all inputs are ints or floats.
+        for name, value in (
+            ("days", days),
+            ("seconds", seconds),
+            ("microseconds", microseconds),
+            ("milliseconds", milliseconds),
+            ("minutes", minutes),
+            ("hours", hours),
+            ("weeks", weeks)
+        ):
+            if not isinstance(value, (int, float)):
+                raise TypeError(
+                    f"unsupported type for timedelta {name} component: {type(value).__name__}"
+                )
 
         # Final values, all integer.
         # s and us fit in 32-bit signed ints; d isn't bounded.

Lib/test/datetimetester.py

@@ -510,6 +510,7 @@ class TestTimeDelta(HarmlessMixedComparison, unittest.TestCase):
 
     def test_constructor(self):
         eq = self.assertEqual
+        ra = self.assertRaises
         td = timedelta
 
         # Check keyword args to constructor
@@ -533,6 +534,15 @@ def test_constructor(self):
         eq(td(seconds=0.001), td(milliseconds=1))
         eq(td(milliseconds=0.001), td(microseconds=1))
 
+        # Check type of args to constructor
+        ra(TypeError, lambda: td(weeks='1'))
+        ra(TypeError, lambda: td(days='1'))
+        ra(TypeError, lambda: td(hours='1'))
+        ra(TypeError, lambda: td(minutes='1'))
+        ra(TypeError, lambda: td(seconds='1'))
+        ra(TypeError, lambda: td(milliseconds='1'))
+        ra(TypeError, lambda: td(microseconds='1'))
+
     def test_computations(self):
         eq = self.assertEqual
         td = timedelta