Issue #25590: Complete attribute names even if they are not yet created

2 files changed, 13 insertions, 3 deletions

diff --git a/Lib/rlcompleter.py b/Lib/rlcompleter.py
index d368876..02e1fa5 100644
--- a/Lib/rlcompleter.py
+++ b/Lib/rlcompleter.py
@@ -160,12 +160,14 @@ class Completer:
             for word in words:
                 if (word[:n] == attr and
                     not (noprefix and word[:n+1] == noprefix)):
+                    match = "%s.%s" % (expr, word)
                     try:
                         val = getattr(thisobject, word)
                     except Exception:
-                        continue  # Exclude properties that are not set
-                    word = self._callable_postfix(val, "%s.%s" % (expr, word))
-                    matches.append(word)
+                        pass  # Include even if attribute not set
+                    else:
+                        match = self._callable_postfix(val, match)
+                    matches.append(match)
             if matches or not noprefix:
                 break
             if noprefix == '_':
diff --git a/Lib/test/test_rlcompleter.py b/Lib/test/test_rlcompleter.py
index fee39bc..8ff75c7 100644
--- a/Lib/test/test_rlcompleter.py
+++ b/Lib/test/test_rlcompleter.py
@@ -92,6 +92,14 @@ class TestRlcompleter(unittest.TestCase):
         self.assertEqual(completer.complete('f.b', 0), 'f.bar')
         self.assertEqual(f.calls, 1)
 
+    def test_uncreated_attr(self):
+        # Attributes like properties and slots should be completed even when
+        # they haven't been created on an instance
+        class Foo:
+            __slots__ = ("bar",)
+        completer = rlcompleter.Completer(dict(f=Foo()))
+        self.assertEqual(completer.complete('f.', 0), 'f.bar')
+
     def test_complete(self):
         completer = rlcompleter.Completer()
         self.assertEqual(completer.complete('', 0), '\t')