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catalyst/zipline/finance/trading.py
T

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8.8 KiB
Python

#
# 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.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# 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.
import logbook
import pandas as pd
from pandas.tslib import normalize_date
from six import string_types
from sqlalchemy import create_engine
from zipline.assets import AssetDBWriter, AssetFinder
from zipline.data.loader import load_market_data
from zipline.utils.calendars import get_calendar
from zipline.utils.memoize import remember_last
log = logbook.Logger('Trading')
class TradingEnvironment(object):
"""
The financial simulations in zipline depend on information
about the benchmark index and the risk free rates of return.
The benchmark index defines the benchmark returns used in
the calculation of performance metrics such as alpha/beta. Many
components, including risk, performance, transforms, and
batch_transforms, need access to a calendar of trading days and
market hours. The TradingEnvironment maintains two time keeping
facilities:
- a DatetimeIndex of trading days for calendar calculations
- a timezone name, which should be local to the exchange
hosting the benchmark index. All dates are normalized to UTC
for serialization and storage, and the timezone is used to
ensure proper rollover through daylight savings and so on.
User code will not normally need to use TradingEnvironment
directly. If you are extending zipline's core financial
components and need to use the environment, you must import the module and
build a new TradingEnvironment object, then pass that TradingEnvironment as
the 'env' arg to your TradingAlgorithm.
Parameters
----------
load : callable, optional
The function that returns benchmark returns and treasury curves.
The treasury curves are expected to be a DataFrame with an index of
dates and columns of the curve names, e.g. '10year', '1month', etc.
bm_symbol : str, optional
The benchmark symbol
exchange_tz : tz-coercable, optional
The timezone of the exchange.
min_date : datetime, optional
The oldest date that we know about in this environment.
max_date : datetime, optional
The most recent date that we know about in this environment.
env_trading_calendar : pd.DatetimeIndex, optional
The calendar of datetimes that define our market hours.
asset_db_path : str or sa.engine.Engine, optional
The path to the assets db or sqlalchemy Engine object to use to
construct an AssetFinder.
"""
# Token used as a substitute for pickling objects that contain a
# reference to a TradingEnvironment
PERSISTENT_TOKEN = "<TradingEnvironment>"
def __init__(
self,
load=None,
bm_symbol='^GSPC',
exchange_tz="US/Eastern",
trading_calendar=None,
asset_db_path=':memory:'
):
self.bm_symbol = bm_symbol
if not load:
load = load_market_data
if not trading_calendar:
trading_calendar = get_calendar("NYSE")
self.benchmark_returns, self.treasury_curves = load(
trading_calendar.day,
trading_calendar.schedule.index,
self.bm_symbol,
)
self.exchange_tz = exchange_tz
if isinstance(asset_db_path, string_types):
asset_db_path = 'sqlite:///' + asset_db_path
self.engine = engine = create_engine(asset_db_path)
else:
self.engine = engine = asset_db_path
if engine is not None:
AssetDBWriter(engine).init_db()
self.asset_finder = AssetFinder(engine)
else:
self.asset_finder = None
def write_data(self, **kwargs):
"""Write data into the asset_db.
Parameters
----------
**kwargs
Forwarded to AssetDBWriter.write
"""
AssetDBWriter(self.engine).write(**kwargs)
class SimulationParameters(object):
def __init__(self, start_session, end_session,
trading_calendar,
capital_base=10e3,
emission_rate='daily',
data_frequency='daily',
arena='backtest'):
assert type(start_session) == pd.Timestamp
assert type(end_session) == pd.Timestamp
assert trading_calendar is not None, \
"Must pass in trading calendar!"
assert start_session <= end_session, \
"Period start falls after period end."
assert start_session <= trading_calendar.last_trading_session, \
"Period start falls after the last known trading day."
assert end_session >= trading_calendar.first_trading_session, \
"Period end falls before the first known trading day."
# chop off any minutes or hours on the given start and end dates,
# as we only support session labels here (and we represent session
# labels as midnight UTC).
self._start_session = normalize_date(start_session)
self._end_session = normalize_date(end_session)
self._capital_base = capital_base
self._emission_rate = emission_rate
self._data_frequency = data_frequency
# copied to algorithm's environment for runtime access
self._arena = arena
self._trading_calendar = trading_calendar
if not trading_calendar.is_session(self._start_session):
# if the start date is not a valid session in this calendar,
# push it forward to the first valid session
self._start_session = trading_calendar.minute_to_session_label(
self._start_session
)
if not trading_calendar.is_session(self._end_session):
# if the end date is not a valid session in this calendar,
# pull it backward to the last valid session before the given
# end date.
self._end_session = trading_calendar.minute_to_session_label(
self._end_session, direction="previous"
)
self._first_open = trading_calendar.open_and_close_for_session(
self._start_session
)[0]
self._last_close = trading_calendar.open_and_close_for_session(
self._end_session
)[1]
@property
def capital_base(self):
return self._capital_base
@property
def emission_rate(self):
return self._emission_rate
@property
def data_frequency(self):
return self._data_frequency
@data_frequency.setter
def data_frequency(self, val):
self._data_frequency = val
@property
def arena(self):
return self._arena
@arena.setter
def arena(self, val):
self._arena = val
@property
def start_session(self):
return self._start_session
@property
def end_session(self):
return self._end_session
@property
def first_open(self):
return self._first_open
@property
def last_close(self):
return self._last_close
@property
@remember_last
def sessions(self):
return self._trading_calendar.sessions_in_range(
self.start_session,
self.end_session
)
def create_new(self, start_session, end_session):
return SimulationParameters(
start_session,
end_session,
self._trading_calendar,
capital_base=self.capital_base,
emission_rate=self.emission_rate,
data_frequency=self.data_frequency,
arena=self.arena
)
def __repr__(self):
return """
{class_name}(
start_session={start_session},
end_session={end_session},
capital_base={capital_base},
data_frequency={data_frequency},
emission_rate={emission_rate},
first_open={first_open},
last_close={last_close})\
""".format(class_name=self.__class__.__name__,
start_session=self.start_session,
end_session=self.end_session,
capital_base=self.capital_base,
data_frequency=self.data_frequency,
emission_rate=self.emission_rate,
first_open=self.first_open,
last_close=self.last_close)
def noop_load(*args, **kwargs):
"""
A method that can be substituted in as the load method in a
TradingEnvironment to prevent it from loading benchmarks.
Accepts any arguments, but returns only a tuple of Nones regardless
of input.
"""
return None, None