From 5fcb2de59b44968512edc28cdfd5c4490853f609 Mon Sep 17 00:00:00 2001
From: Thomas Wiecki <thomas.wiecki@gmail.com>
Date: Fri, 6 Jul 2012 11:54:40 -0400
Subject: [PATCH] ndicts are now deepcopyable.

---
 tests/test_ndict.py             | 32 ++++++++++++++++++++++++++++----
 zipline/utils/protocol_utils.py |  3 +++
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/tests/test_ndict.py b/tests/test_ndict.py
index 9d72e732..845bb97d 100644
--- a/tests/test_ndict.py
+++ b/tests/test_ndict.py
@@ -1,6 +1,8 @@
 from datetime import datetime
 import pytz
 
+from copy import deepcopy
+
 from zipline.utils.protocol_utils import ndict
 
 def test_ndict():
@@ -54,10 +56,32 @@ def test_ndict():
     del nd['x']
     assert not nd.has_key('x')
     assert nd.get('x') is None
-    
-    
+
+
     for n in xrange(1000):
         dt = datetime.utcnow().replace(tzinfo=pytz.utc)
         nd2 = ndict({"dt":dt, "otherdata":"ishere"*1000, "maybeanint":3})
-    
-    nd2.dt2 = dt
\ No newline at end of file
+
+    nd2.dt2 = dt
+
+def test_ndict_deepcopy():
+    def assert_correctly_copied(orig, copy):
+        assert nd == nd_dc, "Deepcopied ndict should have same keys and values."
+
+        nd_dc.z = 3
+        assert 'z' not in nd, "'z' also added to original ndict."
+
+        nd_dc.y = 10
+        assert nd_dc.y == 10, "value of copied ndict not correctly set."
+        assert nd.y != 10, "value also set of original ndict."
+
+    nd = ndict({'x': 1, 'y': 2})
+    nd_dc = deepcopy(nd)
+    assert_correctly_copied(nd, nd_dc)
+
+    nd = ndict({'x':[1,2,3], 'y': {1: 1}})
+    nd_dc = deepcopy(nd)
+    assert_correctly_copied(nd, nd_dc)
+    nd_dc.x.append(4)
+    assert nd_dc.x[-1] == 4, "not correctly appended to copied."
+    assert nd.x[-1] != 4, "also copied to original."
\ No newline at end of file
diff --git a/zipline/utils/protocol_utils.py b/zipline/utils/protocol_utils.py
index 7149a7c1..c74c81f2 100644
--- a/zipline/utils/protocol_utils.py
+++ b/zipline/utils/protocol_utils.py
@@ -55,6 +55,9 @@ class ndict(MutableMapping):
     # Abstact Overloads
     # -----------------
 
+    def __deepcopy__(self, memo):
+        return ndict(copy.deepcopy(self.__internal))
+
     def __setattr__(self, key, value):
         if key == 'cls' or key == '__internal' or '_ndict' in key:
             super(ndict, self).__setattr__(key, value)