From 5f4d8817e80aaf72ce207401aa61a3604b81f3f9 Mon Sep 17 00:00:00 2001
From: Thomas Wiecki <thomas.wiecki@gmail.com>
Date: Tue, 3 Dec 2013 16:29:17 -0500
Subject: [PATCH] ENH: Add len() functionality to BarData.

---
 zipline/protocol.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/zipline/protocol.py b/zipline/protocol.py
index f037b34c..cc3f0e59 100644
--- a/zipline/protocol.py
+++ b/zipline/protocol.py
@@ -181,3 +181,6 @@ class BarData(object):
 
     def items(self):
         return self._data.items()
+
+    def __len__(self):
+        return len(self._data.keys())