simplify the implementation of NodeKeywords getting rid of __ descriptors appearing there.

CHANGELOG

@@ -1,6 +1,10 @@
 Changes between 2.4.1 and 2.4.2
 -----------------------------------
 
+- fix "-k" matching of tests where "repr" and "attr" and other names would
+  cause wrong matches because of an internal implementation quirk
+  (don't ask) which is now properly implemented. fixes issue345.
+
 - avoid "IOError: Bad Filedescriptor" on pytest shutdown by not closing
   the internal dupped stdout (fix is slightly hand-wavy but work).
 

_pytest/main.py

@@ -170,30 +170,39 @@ def compatproperty(name):
 
 class NodeKeywords(MappingMixin):
     def __init__(self, node):
-        parent = node.parent
-        bases = parent and (parent.keywords._markers,) or ()
-        self._markers = type("dynmarker", bases, {node.name: True})
+        self.node = node
+        self.parent = node.parent
+        self._markers = {node.name: True}
 
     def __getitem__(self, key):
         try:
-            return getattr(self._markers, key)
-        except AttributeError:
-            raise KeyError(key)
+            return self._markers[key]
+        except KeyError:
+            if self.parent is None:
+                raise
+            return self.parent.keywords[key]
 
     def __setitem__(self, key, value):
-        setattr(self._markers, key, value)
+        self._markers[key] = value
 
     def __delitem__(self, key):
-        delattr(self._markers, key)
+        raise ValueError("cannot delete key in keywords dict")
 
     def __iter__(self):
-        return iter(self.keys())
+        seen = set(self._markers)
+        if self.parent is not None:
+            seen.update(self.parent.keywords)
+        return iter(seen)
 
     def __len__(self):
-        return len(self.keys())
+        return len(self.__iter__())
 
     def keys(self):
-        return dir(self._markers)
+        return list(self)
+
+    def __repr__(self):
+        return "<NodeKeywords for node %s>" % (self.node, )
+
 
 class Node(object):
     """ base class for Collector and Item the test collection tree.

bench/bench.py

@@ -7,4 +7,4 @@ if __name__ == '__main__':
     p = pstats.Stats("prof")
     p.strip_dirs()
     p.sort_stats('cumulative')
-    print(p.print_stats(30))
+    print(p.print_stats(50))

testing/test_collection.py

@@ -566,4 +566,25 @@ def test_matchnodes_two_collections_same_file(testdir):
     ])
 
 
+class TestNodekeywords:
+    def test_no_under(self, testdir):
+        modcol = testdir.getmodulecol("""
+            def test_pass(): pass
+            def test_fail(): assert 0
+        """)
+        l = list(modcol.keywords)
+        assert modcol.name in l
+        for x in l:
+            assert not x.startswith("_")
+        assert modcol.name in repr(modcol.keywords)
 
+    def test_issue345(self, testdir):
+        testdir.makepyfile("""
+            def test_should_not_be_selected():
+                assert False, 'I should not have been selected to run'
+
+            def test___repr__():
+                pass
+        """)
+        reprec = testdir.inline_run("-k repr")
+        reprec.assertoutcome(passed=1, failed=0)