From fa5f24fb2acbea27c55783ff381d3d282370967e Mon Sep 17 00:00:00 2001
From: jfkirk <james.f.kirk@gmail.com>
Date: Tue, 25 Aug 2015 16:29:20 -0400
Subject: [PATCH] BUG: Removes default table values causing issues

---
 zipline/assets/asset_writer.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/zipline/assets/asset_writer.py b/zipline/assets/asset_writer.py
index ae9c4227..dbbc1be2 100644
--- a/zipline/assets/asset_writer.py
+++ b/zipline/assets/asset_writer.py
@@ -74,13 +74,11 @@ _futures_defaults = {
 
 # Default values for the exchanges DataFrame
 _exchanges_defaults = {
-    'exchange': None,
     'timezone': None,
 }
 
 # Default values for the root_symbols DataFrame
 _root_symbols_defaults = {
-    'root_symbol': None,
     'root_symbol_id': None,
     'sector': None,
     'description': None,