gh-71682: Make pprint.pformat always order sets

Lib/pprint.py

@@ -589,6 +589,37 @@ def _safe_repr(self, object, context, maxlevels, level):
             del context[objid]
             return format % ", ".join(components), readable, recursive
 
+        if (issubclass(typ, set) and r is set.__repr__) or \
+            (issubclass(typ, frozenset) and r is frozenset.__repr__):
+            if not object:
+                return repr(object), True, False
+            if typ is set:
+                format = "{%s}"
+            else:
+                format = typ.__name__ + "({%s})"
+            objid = id(object)
+            if maxlevels and level >= maxlevels:
+                return "{...}", False, objid in context
+            if objid in context:
+                return _recursion(object), False, True
+            context[objid] = 1
+            readable = True
+            recursive = False
+            components = []
+            append = components.append
+            level += 1
+            items = sorted(object, key=_safe_key)
+            for item in items:
+                orepr, oreadable, orecur = self.format(
+                    item, context, maxlevels, level)
+                append("%s" % orepr)
+                if not oreadable:
+                    readable = False
+                if orecur:
+                    recursive = True
+            del context[objid]
+            return format % ", ".join(components), readable, recursive
+
         rep = repr(object)
         return rep, (rep and not rep.startswith('<')), False
 

Lib/test/test_pprint.py

@@ -474,6 +474,9 @@ def test_subclassing(self):
     def test_set_reprs(self):
         self.assertEqual(pprint.pformat(set()), 'set()')
         self.assertEqual(pprint.pformat(set(range(3))), '{0, 1, 2}')
+        self.assertEqual(pprint.pformat(set([-1, 0, 1])), "{-1, 0, 1}")
+        self.assertEqual(pprint.pformat(set("0123")), "{'0', '1', '2', '3'}")
+        self.assertEqual(pprint.pformat(set("abcd")), "{'a', 'b', 'c', 'd'}")
         self.assertEqual(pprint.pformat(set(range(7)), width=20), '''\
 {0,
  1,
@@ -482,6 +485,9 @@ def test_set_reprs(self):
  4,
  5,
  6}''')
+        self.assertEqual(pprint.pformat(set2([-1, 0, 1])), "set2({-1, 0, 1})")
+        self.assertEqual(pprint.pformat(set2("0123")), "set2({'0', '1', '2', '3'})")
+        self.assertEqual(pprint.pformat(set2("abcd")), "set2({'a', 'b', 'c', 'd'})")
         self.assertEqual(pprint.pformat(set2(range(7)), width=20), '''\
 set2({0,
       1,
@@ -496,6 +502,12 @@ def test_set_reprs(self):
         self.assertEqual(pprint.pformat(frozenset()), 'frozenset()')
         self.assertEqual(pprint.pformat(frozenset(range(3))),
                          'frozenset({0, 1, 2})')
+        self.assertEqual(pprint.pformat(frozenset([-1, 0, 1])),
+                         "frozenset({-1, 0, 1})")
+        self.assertEqual(pprint.pformat(frozenset("0123")),
+                         "frozenset({'0', '1', '2', '3'})")
+        self.assertEqual(pprint.pformat(frozenset("abcd")),
+                         "frozenset({'a', 'b', 'c', 'd'})")
         self.assertEqual(pprint.pformat(frozenset(range(7)), width=20), '''\
 frozenset({0,
            1,
@@ -504,6 +516,12 @@ def test_set_reprs(self):
            4,
            5,
            6})''')
+        self.assertEqual(pprint.pformat(frozenset2([-1, 0, 1])),
+                         "frozenset2({-1, 0, 1})")
+        self.assertEqual(pprint.pformat(frozenset2("0123")),
+                         "frozenset2({'0', '1', '2', '3'})")
+        self.assertEqual(pprint.pformat(frozenset2("abcd")),
+                         "frozenset2({'a', 'b', 'c', 'd'})")
         self.assertEqual(pprint.pformat(frozenset2(range(7)), width=20), '''\
 frozenset2({0,
             1,

Misc/ACKS

@@ -193,6 +193,7 @@ Gawain Bolton
 Carl Friedrich Bolz-Tereick
 Forest Bond
 Gregory Bond
+Ben Bonenfant
 Angelin Booz
 Médéric Boquien
 Matias Bordese

Misc/NEWS.d/next/Library/2020-10-26-14-20-58.bpo-27495.OWavSt.rst

@@ -0,0 +1 @@
+Update the `pprint` module to always order the contents of `set` and `frozenset` objects.