Merge pull request #1449 from quantopian/getitem-is-not-getattr

MAINT: remove __getitem__ as alias of __getattr__

Author: llllllllll

tests/test_algorithm.py

@@ -1448,9 +1448,10 @@ def before_trading_start(context, data):
                     assert (context.hd_portfolio.__dict__[k]
                             == bts_portfolio.__dict__[k])
             record(pos_value=bts_portfolio.positions_value)
-            record(pos_amount=bts_portfolio.positions[sid(3)]['amount'])
-            record(last_sale_price=bts_portfolio.positions[sid(3)]
-                   ['last_sale_price'])
+            record(pos_amount=bts_portfolio.positions[sid(3)].amount)
+            record(
+                last_sale_price=bts_portfolio.positions[sid(3)].last_sale_price
+            )
         def handle_data(context, data):
             if not context.ordered:
                 order(sid(3), 1)

tests/test_perf_tracking.py

@@ -111,26 +111,26 @@ def check_account(account,
     # so net and gross leverage are equal.
 
     np.testing.assert_allclose(settled_cash,
-                               account['settled_cash'], rtol=1e-3)
+                               account.settled_cash, rtol=1e-3)
     np.testing.assert_allclose(equity_with_loan,
-                               account['equity_with_loan'], rtol=1e-3)
+                               account.equity_with_loan, rtol=1e-3)
     np.testing.assert_allclose(total_positions_value,
-                               account['total_positions_value'], rtol=1e-3)
+                               account.total_positions_value, rtol=1e-3)
     np.testing.assert_allclose(total_positions_exposure,
-                               account['total_positions_exposure'], rtol=1e-3)
+                               account.total_positions_exposure, rtol=1e-3)
     np.testing.assert_allclose(regt_equity,
-                               account['regt_equity'], rtol=1e-3)
+                               account.regt_equity, rtol=1e-3)
     np.testing.assert_allclose(available_funds,
-                               account['available_funds'], rtol=1e-3)
+                               account.available_funds, rtol=1e-3)
     np.testing.assert_allclose(excess_liquidity,
-                               account['excess_liquidity'], rtol=1e-3)
+                               account.excess_liquidity, rtol=1e-3)
     np.testing.assert_allclose(cushion,
-                               account['cushion'], rtol=1e-3)
-    np.testing.assert_allclose(leverage, account['leverage'], rtol=1e-3)
+                               account.cushion, rtol=1e-3)
+    np.testing.assert_allclose(leverage, account.leverage, rtol=1e-3)
     np.testing.assert_allclose(net_leverage,
-                               account['net_leverage'], rtol=1e-3)
+                               account.net_leverage, rtol=1e-3)
     np.testing.assert_allclose(net_liquidation,
-                               account['net_liquidation'], rtol=1e-3)
+                               account.net_liquidation, rtol=1e-3)
 
 
 def create_txn(asset, dt, price, amount):
@@ -368,28 +368,28 @@ def test_split_long_position(self):
 
         # Validate that the account attributes were updated.
         account = results[1]['account']
-        self.assertEqual(float('inf'), account['day_trades_remaining'])
+        self.assertEqual(float('inf'), account.day_trades_remaining)
         # this is a long only portfolio that is only partially invested
         # so net and gross leverage are equal.
-        np.testing.assert_allclose(0.198, account['leverage'], rtol=1e-3)
-        np.testing.assert_allclose(0.198, account['net_leverage'], rtol=1e-3)
-        np.testing.assert_allclose(8020, account['regt_equity'], rtol=1e-3)
-        self.assertEqual(float('inf'), account['regt_margin'])
-        np.testing.assert_allclose(8020, account['available_funds'], rtol=1e-3)
-        self.assertEqual(0, account['maintenance_margin_requirement'])
+        np.testing.assert_allclose(0.198, account.leverage, rtol=1e-3)
+        np.testing.assert_allclose(0.198, account.net_leverage, rtol=1e-3)
+        np.testing.assert_allclose(8020, account.regt_equity, rtol=1e-3)
+        self.assertEqual(float('inf'), account.regt_margin)
+        np.testing.assert_allclose(8020, account.available_funds, rtol=1e-3)
+        self.assertEqual(0, account.maintenance_margin_requirement)
         np.testing.assert_allclose(10000,
-                                   account['equity_with_loan'], rtol=1e-3)
-        self.assertEqual(float('inf'), account['buying_power'])
-        self.assertEqual(0, account['initial_margin_requirement'])
-        np.testing.assert_allclose(8020, account['excess_liquidity'],
+                                   account.equity_with_loan, rtol=1e-3)
+        self.assertEqual(float('inf'), account.buying_power)
+        self.assertEqual(0, account.initial_margin_requirement)
+        np.testing.assert_allclose(8020, account.excess_liquidity,
                                    rtol=1e-3)
-        np.testing.assert_allclose(8020, account['settled_cash'], rtol=1e-3)
-        np.testing.assert_allclose(10000, account['net_liquidation'],
+        np.testing.assert_allclose(8020, account.settled_cash, rtol=1e-3)
+        np.testing.assert_allclose(10000, account.net_liquidation,
                                    rtol=1e-3)
-        np.testing.assert_allclose(0.802, account['cushion'], rtol=1e-3)
-        np.testing.assert_allclose(1980, account['total_positions_value'],
+        np.testing.assert_allclose(0.802, account.cushion, rtol=1e-3)
+        np.testing.assert_allclose(1980, account.total_positions_value,
                                    rtol=1e-3)
-        self.assertEqual(0, account['accrued_interest'])
+        self.assertEqual(0, account.accrued_interest)
 
         for i, result in enumerate(results):
             for perf_kind in ('daily_perf', 'cumulative_perf'):
@@ -1346,10 +1346,10 @@ def test_long_position(self):
 
         self.assertEqual(
             pp.positions[1].last_sale_price,
-            trades[-1]['price'],
+            trades[-1].price,
             "last sale should be same as last trade. \
             expected {exp} actual {act}".format(
-                exp=trades[-1]['price'],
+                exp=trades[-1].price,
                 act=pp.positions[1].last_sale_price)
         )
 
@@ -1456,7 +1456,7 @@ def test_short_position(self):
 
         self.assertEqual(
             pp.positions[1].last_sale_price,
-            trades_1[-1]['price'],
+            trades_1[-1].price,
             "last sale should be price of last trade"
         )
 

zipline/finance/controls.py

@@ -394,5 +394,5 @@ def validate(self,
         """
         Fail if the leverage is greater than the allowed leverage.
         """
-        if _account['leverage'] > self.max_leverage:
+        if _account.leverage > self.max_leverage:
             self.fail()

zipline/protocol.py

@@ -1,5 +1,5 @@
 #
-# Copyright 2013 Quantopian, Inc.
+# Copyright 2016 Quantopian, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -12,10 +12,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from warnings import warn
+
 import pandas as pd
 
 from .utils.enum import enum
-
 from zipline._protocol import BarData  # noqa
 
 
@@ -61,16 +62,7 @@ class Event(object):
 
     def __init__(self, initial_values=None):
         if initial_values:
-            self.__dict__ = initial_values
-
-    def __getitem__(self, name):
-        return getattr(self, name)
-
-    def __setitem__(self, name, value):
-        setattr(self, name, value)
-
-    def __delitem__(self, name):
-        delattr(self, name)
+            self.__dict__.update(initial_values)
 
     def keys(self):
         return self.__dict__.keys()
@@ -88,8 +80,52 @@ def to_series(self, index=None):
         return pd.Series(self.__dict__, index=index)
 
 
+def _deprecated_getitem_method(name, attrs):
+    """Create a deprecated ``__getitem__`` method that tells users to use
+    getattr instead.
+
+    Parameters
+    ----------
+    name : str
+        The name of the object in the warning message.
+    attrs : iterable[str]
+        The set of allowed attributes.
+
+    Returns
+    -------
+    __getitem__ : callable[any, str]
+        The ``__getitem__`` method to put in the class dict.
+    """
+    attrs = frozenset(attrs)
+    msg = "'{0}[attr]' is deprecated, please use '{0}.attr' instead".format(
+        name,
+    )
+
+    def __getitem__(self, key):
+        """``__getitem__`` is deprecated, please use attribute access instead.
+        """
+        warn(msg, DeprecationWarning, stacklevel=1)
+        if key in attrs:
+            return self.__dict__[key]
+        raise KeyError(key)
+
+    return __getitem__
+
+
 class Order(Event):
-    pass
+    # If you are adding new attributes, don't update this set. This method
+    # is deprecated to normal attribute access so we don't want to encourage
+    # new usages.
+    __getitem__ = _deprecated_getitem_method(
+        'order', {
+            'dt',
+            'sid',
+            'amount',
+            'stop',
+            'limit',
+            'id',
+        },
+    )
 
 
 class Portfolio(object):
@@ -105,12 +141,26 @@ def __init__(self):
         self.start_date = None
         self.positions_value = 0.0
 
-    def __getitem__(self, key):
-        return self.__dict__[key]
-
     def __repr__(self):
         return "Portfolio({0})".format(self.__dict__)
 
+    # If you are adding new attributes, don't update this set. This method
+    # is deprecated to normal attribute access so we don't want to encourage
+    # new usages.
+    __getitem__ = _deprecated_getitem_method(
+        'portfolio', {
+            'capital_used',
+            'starting_cash',
+            'portfolio_value',
+            'pnl',
+            'returns',
+            'cash',
+            'positions',
+            'start_date',
+            'positions_value',
+        },
+    )
+
 
 class Account(object):
     '''
@@ -139,12 +189,34 @@ def __init__(self):
         self.net_leverage = 0.0
         self.net_liquidation = 0.0
 
-    def __getitem__(self, key):
-        return self.__dict__[key]
-
     def __repr__(self):
         return "Account({0})".format(self.__dict__)
 
+    # If you are adding new attributes, don't update this set. This method
+    # is deprecated to normal attribute access so we don't want to encourage
+    # new usages.
+    __getitem__ = _deprecated_getitem_method(
+        'account', {
+            'settled_cash',
+            'accrued_interest',
+            'buying_power',
+            'equity_with_loan',
+            'total_positions_value',
+            'total_positions_exposure',
+            'regt_equity',
+            'regt_margin',
+            'initial_margin_requirement',
+            'maintenance_margin_requirement',
+            'available_funds',
+            'excess_liquidity',
+            'cushion',
+            'day_trades_remaining',
+            'leverage',
+            'net_leverage',
+            'net_liquidation',
+        },
+    )
+
 
 class Position(object):
 
@@ -155,12 +227,22 @@ def __init__(self, sid):
         self.last_sale_price = 0.0
         self.last_sale_date = None
 
-    def __getitem__(self, key):
-        return self.__dict__[key]
-
     def __repr__(self):
         return "Position({0})".format(self.__dict__)
 
+    # If you are adding new attributes, don't update this set. This method
+    # is deprecated to normal attribute access so we don't want to encourage
+    # new usages.
+    __getitem__ = _deprecated_getitem_method(
+        'position', {
+            'sid',
+            'amount',
+            'cost_basis',
+            'last_sale_price',
+            'last_sale_date',
+        },
+    )
+
 
 class Positions(dict):