Better error message on access to non-existing attribute

Author: ksonj

python/pyspark/sql/dataframe.py

@@ -633,7 +633,8 @@ def __getattr__(self, name):
         [Row(age=2), Row(age=5)]
         """
         if name not in self.columns:
-            raise AttributeError("No such column: %s" % name)
+            raise AttributeError(
+                "'%s' object has no attribute '%s'" % (self.__class__.__name__, name))
         jc = self._jdf.apply(name)
         return Column(jc)