From 0e0fecf4ee73144604085a45411de17577800ac2 Mon Sep 17 00:00:00 2001
From: fawce <fawce@quantopian.com>
Date: Thu, 21 Mar 2013 15:13:56 -0400
Subject: [PATCH] allows config to force no datasources by passing a None.
 absence of the parameter triggers the default.

---
 zipline/utils/simfactory.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/zipline/utils/simfactory.py b/zipline/utils/simfactory.py
index 2355745a..eb8008e7 100644
--- a/zipline/utils/simfactory.py
+++ b/zipline/utils/simfactory.py
@@ -76,8 +76,8 @@ def create_test_zipline(**config):
             test_algo.sim_params,
             concurrent=concurrent_trades
         )
-
-    test_algo.set_sources([trade_source])
+    if trade_source:
+        test_algo.set_sources([trade_source])
 
     #-------------------
     # Transforms