Index: Python-3.3.0/Lib/unittest/mock.py
===================================================================
--- Python-3.3.0.orig/Lib/unittest/mock.py
+++ Python-3.3.0/Lib/unittest/mock.py
@@ -2188,6 +2188,8 @@ def mock_open(mock=None, read_data=''):
     handle.write.return_value = None
     handle.__enter__.return_value = handle
     handle.read.return_value = read_data
+    handle.readline.side_effect = map(lambda x: '{}\n'.format(x), read_data.split('\n'))
+    handle.readlines.return_value = list(map(lambda x: '{}\n'.format(x), read_data.split('\n')))
 
     mock.return_value = handle
     return mock