Files
catalyst/zipline/finance/trading.py
T
Eddie Hebert 36319122cc PERF: Change asset finder to be backed by sqlite3.
Attack the startup bottleneck of creating the asset finders caches for a
large universe, which was between 1-2 seconds on development and
production machines.

Instead, allow the AssetFinder to be passed a sqlite3 file that has
already been populated and then hydrate asset objects only when an
equity is referenced for the first time.

To create aforementioned sqlite3, create an AssetFinder with an db_path
and `create_table` set to True. If `create_table` is set to False, the
prepopulated data in the sqlite file found at db_path will be used.

Default behavior is to use an in memory database.

Behavior that changes:

- Fuzzy lookup now only works on one character, that character needs to be
specified at write/metadata consumption time, since the fuzzy lookup key
is created by dropping the character from each symbol.

- Overwriting partially written metadata is no longer
  supported. i.e. some unit tests allowed for inserting just the identifier,
  and then later updating the symbol, end_date, etc.

  Instead of building an upsert behavior at this time, this patch
  changes the unit tests so that the data for each asset is only
  inserted once.

Other notes:

- populate_cache is now removed, since there is no longer a two step
  process of inserting metadata and then realizing that metadata into
  assets. _spawn_asset is rolled into insert_metadata, so that a call to
  insert_metadata both converts the metadata and makes it available in
  the data store.
2015-07-14 09:54:38 -04:00

552 lines
19 KiB
Python

#
# Copyright 2014 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 bisect
import logbook
import datetime
from functools import wraps
import pandas as pd
import numpy as np
from zipline.data.loader import load_market_data
from zipline.utils import tradingcalendar
from zipline.assets import AssetFinder
from zipline.errors import UpdateAssetFinderTypeError
log = logbook.Logger('Trading')
# 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.
#
# This module maintains a global variable, environment, which is
# subsequently referenced directly by zipline financial
# components. To set the environment, you can set the property on
# the module directly:
# from zipline.finance import trading
# trading.environment = TradingEnvironment()
#
# or if you want to switch the environment for a limited context
# you can use a TradingEnvironment in a with clause:
# lse = TradingEnvironment(bm_index="^FTSE", exchange_tz="Europe/London")
# with lse:
# the code here will have lse as the global trading.environment
# algo.run(start, end)
#
# User code will not normally need to use TradingEnvironment
# directly. If you are extending zipline's core financial
# compponents and need to use the environment, you must import the module
# NOT the variable. If you import the module, you will get a
# reference to the environment at import time, which will prevent
# your code from responding to user code that changes the global
# state.
environment = None
class NoFurtherDataError(Exception):
"""
Thrown when next trading is attempted at the end of available data.
"""
pass
class TradingEnvironment(object):
@classmethod
def instance(cls):
global environment
if not environment:
environment = TradingEnvironment()
return environment
def __init__(
self,
load=None,
bm_symbol='^GSPC',
exchange_tz="US/Eastern",
max_date=None,
env_trading_calendar=tradingcalendar
):
"""
@load is 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.
"""
self.trading_day = env_trading_calendar.trading_day.copy()
# `tc_td` is short for "trading calendar trading days"
tc_td = env_trading_calendar.trading_days
if max_date:
self.trading_days = tc_td[tc_td <= max_date].copy()
else:
self.trading_days = tc_td.copy()
self.first_trading_day = self.trading_days[0]
self.last_trading_day = self.trading_days[-1]
self.early_closes = env_trading_calendar.get_early_closes(
self.first_trading_day, self.last_trading_day)
self.open_and_closes = env_trading_calendar.open_and_closes.loc[
self.trading_days]
self.prev_environment = self
self.bm_symbol = bm_symbol
if not load:
load = load_market_data
self.benchmark_returns, self.treasury_curves = \
load(self.trading_day, self.trading_days, self.bm_symbol)
if max_date:
tr_c = self.treasury_curves
# Mask the treasury curves down to the current date.
# In the case of live trading, the last date in the treasury
# curves would be the day before the date considered to be
# 'today'.
self.treasury_curves = tr_c[tr_c.index <= max_date]
self.exchange_tz = exchange_tz
self.asset_finder = AssetFinder()
def __enter__(self, *args, **kwargs):
global environment
self.prev_environment = environment
environment = self
# return value here is associated with "as such_and_such" on the
# with clause.
return self
def __exit__(self, exc_type, exc_val, exc_tb):
global environment
environment = self.prev_environment
# signal that any exceptions need to be propagated up the
# stack.
return False
def update_asset_finder(self,
clear_metadata=False,
asset_finder=None,
asset_metadata=None,
identifiers=None):
"""
Updates the AssetFinder using the provided asset metadata and
identifiers.
If clear_metadata is True, all metadata and assets held in the
asset_finder will be erased before new metadata is provided.
If asset_finder is provided, the existing asset_finder will be replaced
outright with the new asset_finder.
If asset_metadata is provided, the existing metadata will be cleared
and replaced with the provided metadata.
All identifiers will be inserted in the asset metadata if they are not
already present.
:param clear_metadata: A boolean
:param asset_finder: An AssetFinder object to replace the environment's
existing asset_finder
:param asset_metadata: A dict, DataFrame, or readable object
:param identifiers: A list of identifiers to be inserted
:return:
"""
if clear_metadata:
self.asset_finder.clear_metadata()
if asset_finder is not None:
if not isinstance(asset_finder, AssetFinder):
raise UpdateAssetFinderTypeError(cls=asset_finder.__class__)
self.asset_finder = asset_finder
if asset_metadata is not None:
self.asset_finder.clear_metadata()
self.asset_finder.consume_metadata(asset_metadata)
if identifiers is not None:
self.asset_finder.consume_identifiers(identifiers)
def normalize_date(self, test_date):
test_date = pd.Timestamp(test_date, tz='UTC')
return pd.tseries.tools.normalize_date(test_date)
def utc_dt_in_exchange(self, dt):
return pd.Timestamp(dt).tz_convert(self.exchange_tz)
def exchange_dt_in_utc(self, dt):
return pd.Timestamp(dt, tz=self.exchange_tz).tz_convert('UTC')
def is_market_hours(self, test_date):
if not self.is_trading_day(test_date):
return False
mkt_open, mkt_close = self.get_open_and_close(test_date)
return test_date >= mkt_open and test_date <= mkt_close
def is_trading_day(self, test_date):
dt = self.normalize_date(test_date)
return (dt in self.trading_days)
def next_trading_day(self, test_date):
dt = self.normalize_date(test_date)
delta = datetime.timedelta(days=1)
while dt <= self.last_trading_day:
dt += delta
if dt in self.trading_days:
return dt
return None
def previous_trading_day(self, test_date):
dt = self.normalize_date(test_date)
delta = datetime.timedelta(days=-1)
while self.first_trading_day < dt:
dt += delta
if dt in self.trading_days:
return dt
return None
def add_trading_days(self, n, date):
"""
Adds n trading days to date. If this would fall outside of the
trading calendar, a NoFurtherDataError is raised.
:Arguments:
n : int
The number of days to add to date, this can be positive or
negative.
date : datetime
The date to add to.
:Returns:
new_date : datetime
n trading days added to date.
"""
if n == 1:
return self.next_trading_day(date)
if n == -1:
return self.previous_trading_day(date)
idx = self.get_index(date) + n
if idx < 0 or idx >= len(self.trading_days):
raise NoFurtherDataError('Cannot add %d days to %s' % (n, date))
return self.trading_days[idx]
def days_in_range(self, start, end):
mask = ((self.trading_days >= start) &
(self.trading_days <= end))
return self.trading_days[mask]
def opens_in_range(self, start, end):
return self.open_and_closes.market_open.loc[start:end]
def closes_in_range(self, start, end):
return self.open_and_closes.market_close.loc[start:end]
def minutes_for_days_in_range(self, start, end):
"""
Get all market minutes for the days between start and end, inclusive.
"""
start_date = self.normalize_date(start)
end_date = self.normalize_date(end)
all_minutes = []
for day in self.days_in_range(start_date, end_date):
day_minutes = self.market_minutes_for_day(day)
all_minutes.append(day_minutes)
# Concatenate all minutes and truncate minutes before start/after end.
return pd.DatetimeIndex(
np.concatenate(all_minutes), copy=False, tz='UTC',
)
def next_open_and_close(self, start_date):
"""
Given the start_date, returns the next open and close of
the market.
"""
next_open = self.next_trading_day(start_date)
if next_open is None:
raise NoFurtherDataError(
"Attempt to backtest beyond available history. \
Last successful date: %s" % self.last_trading_day)
return self.get_open_and_close(next_open)
def previous_open_and_close(self, start_date):
"""
Given the start_date, returns the previous open and close of the
market.
"""
previous = self.previous_trading_day(start_date)
if previous is None:
raise NoFurtherDataError(
"Attempt to backtest beyond available history. "
"First successful date: %s" % self.first_trading_day)
return self.get_open_and_close(previous)
def next_market_minute(self, start):
"""
Get the next market minute after @start. This is either the immediate
next minute, or the open of the next market day after start.
"""
next_minute = start + datetime.timedelta(minutes=1)
if self.is_market_hours(next_minute):
return next_minute
return self.next_open_and_close(start)[0]
def previous_market_minute(self, start):
"""
Get the next market minute before @start. This is either the immediate
previous minute, or the close of the market day before start.
"""
prev_minute = start - datetime.timedelta(minutes=1)
if self.is_market_hours(prev_minute):
return prev_minute
return self.previous_open_and_close(start)[1]
def get_open_and_close(self, day):
index = self.open_and_closes.index.get_loc(day.date())
todays_minutes = self.open_and_closes.values[index]
return todays_minutes[0], todays_minutes[1]
def market_minutes_for_day(self, stamp):
market_open, market_close = self.get_open_and_close(stamp)
return pd.date_range(market_open, market_close, freq='T')
def open_close_window(self, start, count, offset=0, step=1):
"""
Return a DataFrame containing `count` market opens and closes,
beginning with `start` + `offset` days and continuing `step` minutes at
a time.
"""
# TODO: Correctly handle end of data.
start_idx = self.get_index(start) + offset
stop_idx = start_idx + (count * step)
index = np.arange(start_idx, stop_idx, step)
return self.open_and_closes.iloc[index]
def market_minute_window(self, start, count, step=1):
"""
Return a DatetimeIndex containing `count` market minutes, starting with
`start` and continuing `step` minutes at a time.
"""
if not self.is_market_hours(start):
raise ValueError("market_minute_window starting at "
"non-market time {minute}".format(minute=start))
all_minutes = []
current_day_minutes = self.market_minutes_for_day(start)
first_minute_idx = current_day_minutes.searchsorted(start)
minutes_in_range = current_day_minutes[first_minute_idx::step]
# Build up list of lists of days' market minutes until we have count
# minutes stored altogether.
while True:
if len(minutes_in_range) >= count:
# Truncate off extra minutes
minutes_in_range = minutes_in_range[:count]
all_minutes.append(minutes_in_range)
count -= len(minutes_in_range)
if count <= 0:
break
if step > 0:
start, _ = self.next_open_and_close(start)
current_day_minutes = self.market_minutes_for_day(start)
else:
_, start = self.previous_open_and_close(start)
current_day_minutes = self.market_minutes_for_day(start)
minutes_in_range = current_day_minutes[::step]
# Concatenate all the accumulated minutes.
return pd.DatetimeIndex(
np.concatenate(all_minutes), copy=False, tz='UTC',
)
def trading_day_distance(self, first_date, second_date):
first_date = self.normalize_date(first_date)
second_date = self.normalize_date(second_date)
# TODO: May be able to replace the following with searchsorted.
# Find leftmost item greater than or equal to day
i = bisect.bisect_left(self.trading_days, first_date)
if i == len(self.trading_days): # nothing found
return None
j = bisect.bisect_left(self.trading_days, second_date)
if j == len(self.trading_days):
return None
return j - i
def get_index(self, dt):
"""
Return the index of the given @dt, or the index of the preceding
trading day if the given dt is not in the trading calendar.
"""
ndt = self.normalize_date(dt)
if ndt in self.trading_days:
return self.trading_days.searchsorted(ndt)
else:
return self.trading_days.searchsorted(ndt) - 1
class SimulationParameters(object):
def __init__(self, period_start, period_end,
capital_base=10e3,
emission_rate='daily',
data_frequency='daily'):
self.period_start = period_start
self.period_end = period_end
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 = 'backtest'
self._update_internal()
def _update_internal(self):
# This is the global environment for trading simulation.
environment = TradingEnvironment.instance()
assert self.period_start <= self.period_end, \
"Period start falls after period end."
assert self.period_start <= environment.last_trading_day, \
"Period start falls after the last known trading day."
assert self.period_end >= environment.first_trading_day, \
"Period end falls before the first known trading day."
self.first_open = self.calculate_first_open()
self.last_close = self.calculate_last_close()
start_index = \
environment.get_index(self.first_open)
end_index = environment.get_index(self.last_close)
# take an inclusive slice of the environment's
# trading_days.
self.trading_days = \
environment.trading_days[start_index:end_index + 1]
def calculate_first_open(self):
"""
Finds the first trading day on or after self.period_start.
"""
first_open = self.period_start
one_day = datetime.timedelta(days=1)
while not environment.is_trading_day(first_open):
first_open = first_open + one_day
mkt_open, _ = environment.get_open_and_close(first_open)
return mkt_open
def calculate_last_close(self):
"""
Finds the last trading day on or before self.period_end
"""
last_close = self.period_end
one_day = datetime.timedelta(days=1)
while not environment.is_trading_day(last_close):
last_close = last_close - one_day
_, mkt_close = environment.get_open_and_close(last_close)
return mkt_close
@property
def days_in_period(self):
"""return the number of trading days within the period [start, end)"""
return len(self.trading_days)
def __repr__(self):
return """
{class_name}(
period_start={period_start},
period_end={period_end},
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__,
period_start=self.period_start,
period_end=self.period_end,
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 with_environment(asname='env'):
"""
Decorator to automagically pass TradingEnvironment to the function
under the name asname. If the environment is passed explicitly as a keyword
then the explicitly passed value will be used instead.
usage:
with_environment()
def f(env=None):
pass
with_environment(asname='my_env')
def g(my_env=None):
pass
"""
def with_environment_decorator(f):
@wraps(f)
def wrapper(*args, **kwargs):
# inject env into the namespace for the function.
# This doesn't use setdefault so that grabbing the trading env
# is lazy.
if asname not in kwargs:
kwargs[asname] = TradingEnvironment.instance()
return f(*args, **kwargs)
return wrapper
return with_environment_decorator