From f88aacc21447f0b21659ea28ddd4ec503fb308b2 Mon Sep 17 00:00:00 2001
From: Stephen Diehl <stephen.m.diehl@gmail.com>
Date: Wed, 16 May 2012 17:03:16 -0400
Subject: [PATCH] Fix some more oop on transforms.

---
 zipline/core/devsimulator.py     |  8 +++++-
 zipline/finance/movingaverage.py |  4 +--
 zipline/finance/vwap.py          | 14 ++++++----
 zipline/transitions.py           | 48 ++++++++++++++++----------------
 4 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/zipline/core/devsimulator.py b/zipline/core/devsimulator.py
index 37418d06..b1aee965 100644
--- a/zipline/core/devsimulator.py
+++ b/zipline/core/devsimulator.py
@@ -1,11 +1,16 @@
 """
-Simulator hosts all the components necessary to execute a simluation. See :py:method""
+Simulator hosts all the components necessary to execute a simluation.
+See :py:method""
 """
 
 import threading
 from zipline.core import ComponentHost
 
 class AddressAllocator(object):
+    """
+    Produces a iterator of 10000 sockets to allocate as needed.
+    Emulates the API of Qexec's socket allocator.
+    """
 
     def __init__(self, ns):
         self.idx = 0
@@ -28,6 +33,7 @@ class Simulator(ComponentHost):
     zmq_flavor = 'thread'
 
     def __init__(self, addresses):
+        # TODO: rethink this
         ComponentHost.__init__(self, addresses)
         self.subthreads = []
         self.running = False
diff --git a/zipline/finance/movingaverage.py b/zipline/finance/movingaverage.py
index bdd3bfc8..ce5b2827 100644
--- a/zipline/finance/movingaverage.py
+++ b/zipline/finance/movingaverage.py
@@ -20,7 +20,7 @@ class MovingAverageTransform(BaseTransform):
 
 class MovingAverage(object):
 
-    def __init__(self, daycount):
+    def init(self, daycount):
         self.window = EventWindow(daycount)
         self.total = 0.0
         self.average = 0.0
@@ -43,7 +43,7 @@ class EventWindow(object):
     Tracks a window of the event history. Use an instance to track the events
     inside your window to efficiently calculate rolling statistics.
     """
-    def __init__(self, daycount):
+    def init(self, daycount):
         self.ticks = []
         self.dropped_ticks = []
         self.delta = timedelta(days=daycount)
diff --git a/zipline/finance/vwap.py b/zipline/finance/vwap.py
index 7b435fb0..14ea98ad 100644
--- a/zipline/finance/vwap.py
+++ b/zipline/finance/vwap.py
@@ -1,27 +1,29 @@
-from collections import defaultdict
 from datetime import timedelta
+from collections import defaultdict
 
 from zipline.transforms.base import BaseTransform
 from zipline.finance.movingaverage import EventWindow
 
 class VWAPTransform(BaseTransform):
-    
+
     def init(self, daycount=3):
         self.daycount = daycount
         self.by_sid = defaultdict(self.create_vwap)
-        
+
     def transform(self, event):
         cur = self.by_sid[event.sid]
         cur.update(event)
         self.state['value'] = cur.vwap
         return self.state
-    
+
     def create_vwap(self):
         return DailyVWAP(self.daycount)
 
 class DailyVWAP:
-    """A class that tracks the volume weighted average price
-       based on tick updates."""
+    """
+    A class that tracks the volume weighted average price based on tick
+    updates.
+    """
     def __init__(self, daycount):
         self.window = EventWindow(daycount)
         self.flux = 0.0
diff --git a/zipline/transitions.py b/zipline/transitions.py
index 9a68926f..2e546fc5 100644
--- a/zipline/transitions.py
+++ b/zipline/transitions.py
@@ -35,27 +35,6 @@ class Workflow(Container, Callable):
         else:
             return False
 
-class Flowable:
-
-    @property
-    def state(self):
-        if not hasattr(self, '_state'):
-            self._state = self.initial_state
-        else:
-            return self._state
-
-    @state.setter
-    def state(self, new):
-        if not hasattr(self, '_state'):
-            self._state = self.initial_state
-
-        old = self._state
-
-        if (old, new) in self.workflow:
-            self._state = new
-        else:
-            raise RuntimeError("Invalid State Transition : %s -> %s" %(old, new))
-
 class WorkflowMeta(type):
     """
     Base metaclass component workflows.
@@ -79,9 +58,30 @@ class WorkflowMeta(type):
         if not transitions:
             raise RuntimeError('Must specify initial_state')
 
-        new_class = super(WorkflowMeta, cls).__new__(
-            cls, name, mro+(Flowable,), attrs
-        )
+        new_class = super(WorkflowMeta, cls).__new__(cls, name, mro, attrs)
         new_class.workflow = Workflow(state, transitions, initial_state)
 
         return new_class
+
+class Flowable(object):
+
+    __metaclass__ = WorkflowMeta
+
+    @property
+    def state(self):
+        if not hasattr(self, '_state'):
+            self._state = self.initial_state
+        else:
+            return self._state
+
+    @state.setter
+    def state(self, new):
+        if not hasattr(self, '_state'):
+            self._state = self.initial_state
+
+        old = self._state
+
+        if (old, new) in self.workflow:
+            self._state = new
+        else:
+            raise RuntimeError("Invalid State Transition : %s -> %s" %(old, new))