[Python-checkins] cpython (3.4): Issue #25590: Make rlcompleter only call getattr() once per attribute

Fri Nov 13 18:57:39 EST 2015

https://hg.python.org/cpython/rev/92f989bfeca2
changeset: 99115:92f989bfeca2
branch: 3.4
parent: 99110:9b23f7a94ba9
user: Martin Panter <vadmium+py at gmail.com>
date: Fri Nov 13 22:47:00 2015 +0000
summary:
 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.
files:
 Lib/rlcompleter.py | 17 ++++++++++-------
 Lib/test/test_rlcompleter.py | 13 +++++++++++++
 Misc/NEWS | 3 +++
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/Lib/rlcompleter.py b/Lib/rlcompleter.py
--- a/Lib/rlcompleter.py
+++ b/Lib/rlcompleter.py
@@ -136,20 +136,23 @@
 return []
 
 # get the content of the object, except __builtins__
- words = dir(thisobject)
- if "__builtins__" in words:
- words.remove("__builtins__")
+ words = set(dir(thisobject))
+ words.discard("__builtins__")
 
 if hasattr(thisobject, '__class__'):
- words.append('__class__')
- words.extend(get_class_members(thisobject.__class__))
+ words.add('__class__')
+ words.update(get_class_members(thisobject.__class__))
 matches = []
 n = len(attr)
 for word in words:
- if word[:n] == attr and hasattr(thisobject, word):
- val = getattr(thisobject, word)
+ if word[:n] == attr:
+ 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)
+ matches.sort()
 return matches
 
 def get_class_members(klass):
diff --git a/Lib/test/test_rlcompleter.py b/Lib/test/test_rlcompleter.py
--- a/Lib/test/test_rlcompleter.py
+++ b/Lib/test/test_rlcompleter.py
@@ -64,6 +64,19 @@
 ['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')
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -103,6 +103,9 @@
 Library
 -------
 
+- Issue #25590: In the Readline completer, only call getattr() once per
+ attribute.
+
 - Issue #25498: Fix a crash when garbage-collecting ctypes objects created
 by wrapping a memoryview. This was a regression made in 3.4.3. Based
 on patch by Eryksun.
-- 
Repository URL: https://hg.python.org/cpython
