Files
catalyst/zipline/data/bar_reader.py
T
Andrew Daniels ca5f98be8c BUG: Makes NoData{Before, After}Date subclass NoDataOnDate (#1507)
This allows us to catch and handle all three of these exceptions in
`calc_dividend_ratios`.
2016-09-22 11:43:43 -04:00

139 lines
3.8 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.
from abc import ABCMeta, abstractmethod, abstractproperty
from six import with_metaclass
class NoDataOnDate(Exception):
"""
Raised when a spot price cannot be found for the sid and date.
"""
pass
class NoDataBeforeDate(NoDataOnDate):
pass
class NoDataAfterDate(NoDataOnDate):
pass
class BarReader(with_metaclass(ABCMeta, object)):
@abstractproperty
def data_frequency(self):
pass
@abstractmethod
def load_raw_arrays(self, columns, start_date, end_date, assets):
"""
Parameters
----------
fields : list of str
'open', 'high', 'low', 'close', or 'volume'
start_dt: Timestamp
Beginning of the window range.
end_dt: Timestamp
End of the window range.
sids : list of int
The asset identifiers in the window.
Returns
-------
list of np.ndarray
A list with an entry per field of ndarrays with shape
(minutes in range, sids) with a dtype of float64, containing the
values for the respective field over start and end dt range.
"""
pass
@abstractproperty
def last_available_dt(self):
"""
Returns
-------
dt : pd.Timestamp
The last session for which the reader can provide data.
"""
pass
@abstractproperty
def trading_calendar(self):
"""
Returns the zipline.utils.calendar.trading_calendar used to read
the data. Can be None (if the writer didn't specify it).
"""
pass
@abstractproperty
def first_trading_day(self):
"""
Returns
-------
dt : pd.Timestamp
The first trading day (session) for which the reader can provide
data.
"""
pass
@abstractmethod
def get_value(self, sid, dt, field):
"""
Retrieve the value at the given coordinates.
Parameters
----------
sid : int
The asset identifier.
dt : pd.Timestamp
The timestamp for the desired data point.
field : string
The OHLVC name for the desired data point.
Returns
-------
value : float|int
The value at the given coordinates, ``float`` for OHLC, ``int``
for 'volume'.
Raises
------
NoDataOnDate
If the given dt is not a valid market minute (in minute mode) or
session (in daily mode) according to this reader's tradingcalendar.
"""
pass
@abstractmethod
def get_last_traded_dt(self, asset, dt):
"""
Get the latest minute on or before ``dt`` in which ``asset`` traded.
If there are no trades on or before ``dt``, returns ``pd.NaT``.
Parameters
----------
asset : zipline.asset.Asset
The asset for which to get the last traded minute.
dt : pd.Timestamp
The minute at which to start searching for the last traded minute.
Returns
-------
last_traded : pd.Timestamp
The dt of the last trade for the given asset, using the input
dt as a vantage point.
"""
pass