From 5dc449ba1924e0ce65efd126b94fc174016d738d Mon Sep 17 00:00:00 2001
From: Eddie Hebert <ehebert@quantopian.com>
Date: Wed, 20 Mar 2013 13:19:39 -0400
Subject: [PATCH] MAINT: Changes boolean check for snapshot existence in
 performance.

Small tweak to check for existence of elements using built-in
boolean of lists, instead of checking for `len`.
---
 zipline/finance/performance.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/zipline/finance/performance.py b/zipline/finance/performance.py
index b68eb17d..3b2c1cdd 100644
--- a/zipline/finance/performance.py
+++ b/zipline/finance/performance.py
@@ -215,7 +215,7 @@ class PerformanceTracker(object):
 
                     new_snapshot.append(event)
 
-            if len(new_snapshot) > 0:
+            if new_snapshot:
                 yield date, new_snapshot
 
     def get_portfolio(self):