Issue #25590: Make rlcompleter only call getattr() once per attribute

Previously it was called another time via hasattr(), and both calls were
made once for dir(f) and again for dir(f.__class__).  This includes a
backport of changing from a list to a set from revision 4dbb315fe667.

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_rlcompleter.py b/Lib/test/test_rlcompleter.py
index 2da7fce..927df34 100644
--- a/Lib/test/test_rlcompleter.py
+++ b/Lib/test/test_rlcompleter.py
@@ -64,6 +64,19 @@ class TestRlcompleter(unittest.TestCase):
                          ['egg.{}('.format(x) for x in dir(str)
                           if x.startswith('s')])
 
+    def test_excessive_getattr(self):
+        # Ensure getattr() is invoked no more than once per attribute
+        class Foo:
+            calls = 0
+            @property
+            def bar(self):
+                self.calls += 1
+                return None
+        f = Foo()
+        completer = rlcompleter.Completer(dict(f=f))
+        self.assertEqual(completer.complete('f.b', 0), 'f.bar')
+        self.assertEqual(f.calls, 1)
+
     def test_complete(self):
         completer = rlcompleter.Completer()
         self.assertEqual(completer.complete('', 0), '\t')