use redefined __repr__ method for integer subclass if it exists

Author: sblondon

Lib/pprint.py

@@ -529,7 +529,7 @@ def _safe_repr(self, object, context, maxlevels, level):
 
         r = getattr(typ, "__repr__", None)
 
-        if issubclass(typ, int):
+        if issubclass(typ, int) and r is int.__repr__:
             if self._underscore_numbers:
                 return builtins.format(object, "_d"), True, False
             else:

Lib/test/test_pprint.py

@@ -327,6 +327,14 @@ def test_integer(self):
         self.assertEqual(pprint.pformat(1234567), '1_234_567')
         self.assertEqual(pprint.pformat(1234567, underscore_numbers=False), '1234567')
 
+        class Temperature(int):
+            def __new__(cls, celsius_degrees):
+                return super().__new__(Temperature, celsius_degrees)
+            def __repr__(self):
+                kelvin_degrees = self + 273.15
+                return f"{kelvin_degrees}°K"
+        self.assertEqual(pprint.pformat(Temperature(1000)), '1273.15°K')
+
     def test_sorted_dict(self):
         # Starting in Python 2.5, pprint sorts dict displays by key regardless
         # of how small the dictionary may be.