From f9d3dbff47c7af8a5bf002235f8163b42ef3f074 Mon Sep 17 00:00:00 2001
From: warren-oneill <warren.oneill@grundgruen.com>
Date: Wed, 3 Jun 2015 15:10:54 +0200
Subject: [PATCH] allow passing of data type from data source

---
 zipline/sources/data_source.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/zipline/sources/data_source.py b/zipline/sources/data_source.py
index 1b04734e..de91793a 100644
--- a/zipline/sources/data_source.py
+++ b/zipline/sources/data_source.py
@@ -45,11 +45,12 @@ class DataSource(with_metaclass(ABCMeta)):
         """
         Override this to hand craft conversion of row.
         """
-        row = {target: mapping_func(raw_row[source_key])
-               for target, (mapping_func, source_key)
-               in self.mapping.items()}
-        row.update({'source_id': self.get_hash()})
+        row = {}
         row.update({'type': self.event_type})
+        row.update({target: mapping_func(raw_row[source_key])
+                    for target, (mapping_func, source_key)
+                    in self.mapping.items()})
+        row.update({'source_id': self.get_hash()})
         return row
 
     @property