bpo-27495: Make pprint.pformat always order sets

Author: bbonenfant

Lib/pprint.py

@@ -587,6 +587,37 @@ def _safe_repr(object, context, maxlevels, level, sort_dicts):
         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
+        saferepr = _safe_repr
+        items = sorted(object, key=_safe_key)
+        for item in items:
+            orepr, oreadable, orecur = saferepr(item, context, maxlevels, level, sort_dicts)
+            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

@@ -463,6 +463,9 @@ 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,
@@ -471,6 +474,9 @@ 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,
@@ -485,6 +491,12 @@ 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,
@@ -493,6 +505,12 @@ 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,