Merge pull request #4382 from jtratner/safer-hasattr-in-dir2

Use safe_hasattr in dir2

IPython/core/oinspect.py

@@ -36,6 +36,7 b' from IPython.utils import PyColorize'
 from IPython.utils import io
 from IPython.utils import openpy
 from IPython.utils import py3compat
+from IPython.utils.dir2 import safe_hasattr
 from IPython.utils.text import indent
 from IPython.utils.wildcard import list_namespace
 from IPython.utils.coloransi import *
@@ -258,16 +259,6 b' def call_tip(oinfo, format_call=True):'
 
     return call_line, doc
 
-def safe_hasattr(obj, attr):
-    """In recent versions of Python, hasattr() only catches AttributeError.
-    This catches all errors.
-    """
-    try:
-        getattr(obj, attr)
-        return True
-    except:
-        return False
-
 
 def find_file(obj):
     """Find the absolute path to the file where an object was defined.

IPython/utils/dir2.py

@@ -12,14 +12,25 b''
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
+
+def safe_hasattr(obj, attr):
+    """In recent versions of Python, hasattr() only catches AttributeError.
+    This catches all errors.
+    """
+    try:
+        getattr(obj, attr)
+        return True
+    except:
+        return False
+
+
 def get_class_members(cls):
     ret = dir(cls)
-    if hasattr(cls, '__bases__'):
+    if safe_hasattr(cls, '__bases__'):
         try:
             bases = cls.__bases__
         except AttributeError:
@@ -49,7 +60,7 b' def dir2(obj):'
 
     words = set(dir(obj))
 
-    if hasattr(obj, '__class__'):
+    if safe_hasattr(obj, '__class__'):
         #words.add('__class__')
         words |= set(get_class_members(obj.__class__))
 
@@ -57,14 +68,13 b' def dir2(obj):'
     # for objects with Enthought's traits, add trait_names() list
     # for PyCrust-style, add _getAttributeNames() magic method list
     for attr in ('trait_names', '_getAttributeNames'):
-        if hasattr(obj, attr):
-            try:
-                func = getattr(obj, attr)
-                if callable(func):
-                    words |= set(func())
-            except:
-                # TypeError: obj is class not instance
-                pass
+        try:
+            func = getattr(obj, attr)
+            if callable(func):
+                words |= set(func())
+        except:
+            # TypeError: obj is class not instance
+            pass
 
     # filter out non-string attributes which may be stuffed by dir() calls
     # and poor coding in third-party modules

IPython/utils/tests/test_dir2.py

@@ -50,3 +50,31 b' def test_SubClass_with_trait_names_attr():'
 
     res = dir2(SubClass())
     assert('trait_names' in res)
+
+
+def test_misbehaving_object_without_trait_names():
+    # dir2 shouldn't raise even when objects are dumb and raise
+    # something other than AttribteErrors on bad getattr.
+
+    class BadTraitNames(object):
+        @property
+        def trait_names(self):
+            raise KeyboardInterrupt("This should be caught")
+
+        def some_method(self):
+            pass
+
+    class MisbehavingGetattr(object):
+        def __getattr__(self):
+            raise KeyError("I should be caught")
+
+        def some_method(self):
+            pass
+
+    class SillierWithDir(MisbehavingGetattr):
+        def __dir__(self):
+            return ['some_method']
+
+    for bad_klass in (BadTraitNames, MisbehavingGetattr, SillierWithDir):
+        res = dir2(bad_klass())
+        assert('some_method' in res)