Mine

Index: dsniff/core/flow.py
===================================================================
--- dsniff/core/flow.py	(revision 8)
+++ dsniff/core/flow.py	(working copy)
@@ -50,7 +50,8 @@
 
 class Flow(object):
     __slots__ = ('client', 'server', 'p', 'stime', 'etime',
-                 'state', 'save', 'half', 'callbacks')
+                 'state', 'save', 'half', 'callbacks',
+                 'appid', 'appid_confidence')
     _Half = FlowHalf
 
     def __init__(self, ts, ip):
@@ -66,6 +67,8 @@
         self.stime = self.etime = ts
         self.callbacks = []
         self.save = {}
+        self.appid = self.appid_confidence = None
+
     src = property(lambda self: self.client.addr)
     dst = property(lambda self: self.server.addr)
     sport = property(lambda self: self.client.port)