Merge pull request #3484 from takluyver/i2577

Catch some pathological cases inside oinspect

IPython/core/oinspect.py

@@ -261,6 +261,16 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.
@@ -279,7 +289,7 b' def find_file(obj):'
       The absolute path to the file where the object was defined.
     """
     # get source if obj was decorated with @decorator
-    if hasattr(obj, '__wrapped__'):
+    if safe_hasattr(obj, '__wrapped__'):
         obj = obj.__wrapped__
 
     fname = None
@@ -316,7 +326,7 b' def find_source_lines(obj):'
       The line number where the object definition starts.
     """
     # get source if obj was decorated with @decorator
-    if hasattr(obj, '__wrapped__'):
+    if safe_hasattr(obj, '__wrapped__'):
         obj = obj.__wrapped__
     
     try:
@@ -779,7 +789,7 b' class Inspector:'
                 out['init_docstring'] = init_ds
 
             # Call form docstring for callable instances
-            if hasattr(obj, '__call__'):
+            if safe_hasattr(obj, '__call__'):
                 call_def = self._getdef(obj.__call__, oname)
                 if call_def is not None:
                     out['call_def'] = self.format(call_def)

IPython/core/tests/test_oinspect.py

@@ -158,6 +158,11 b' class SimpleMagics(Magics):'
         "A class-based line/cell magic"
 
 
+class Awkward(object):
+    def __getattr__(self, name):
+        raise Exception(name)
+
+
 def check_calltip(obj, name, call, docstring):
     """Generic check pattern all calltip tests will use"""
     info = inspector.info(obj, name)
@@ -261,6 +266,10 b' def test_info():'
         nt.assert_equal(i['type_name'], 'instance')
         nt.assert_equal(i['docstring'], OldStyle.__doc__)
 
+def test_info_awkward():
+    # Just test that this doesn't throw an error.
+    i = inspector.info(Awkward())
+
 def test_getdoc():
     class A(object):
         """standard docstring"""