[SPARK-4578] fix asDict() with nested Row()

The Row object is created on the fly once the field is accessed, so we should access them by getattr() in asDict(0

Author: Davies Liu <davies@databricks.com>

Closes #3434 from davies/fix_asDict and squashes the following commits:

b20f1e7 [Davies Liu] fix asDict() with nested Row()

1 files changed, 1 insertions, 1 deletions

diff --git a/python/pyspark/sql.py b/python/pyspark/sql.py
index abb284d1e3..ae288471b0 100644
--- a/python/pyspark/sql.py
+++ b/python/pyspark/sql.py
@@ -1178,7 +1178,7 @@ def _create_cls(dataType):
 
         def asDict(self):
             """ Return as a dict """
-            return dict(zip(self.__FIELDS__, self))
+            return dict((n, getattr(self, n)) for n in self.__FIELDS__)
 
         def __repr__(self):
             # call collect __repr__ for nested objects