Files
catalyst/zipline/pipeline/loaders/equity_pricing_loader.py
T
Eddie Hebert e33f6dcdcd MAINT: Move equity data formats out of loader.
Put the logic for reading and writing the equity price and adjustment
data into a module located in data, making it distinct from the pipeline
loader usage of the formats.

This prepares for both incoming changes of how adjustments are written,
(which includes using the bcolz daily reader as an input), as well as
eventually providing the readers to a DataPortal object.
2015-10-09 17:20:19 -04:00

115 lines
3.8 KiB
Python

# Copyright 2015 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 numpy import (
iinfo,
uint32,
)
from zipline.lib.adjusted_array import (
adjusted_array,
)
from zipline.errors import NoFurtherDataError
from .base import PipelineLoader
UINT32_MAX = iinfo(uint32).max
class USEquityPricingLoader(PipelineLoader):
"""
PipelineLoader for US Equity Pricing data
Delegates loading of baselines and adjustments.
"""
def __init__(self, raw_price_loader, adjustments_loader):
self.raw_price_loader = raw_price_loader
# HACK: Pull the calendar off our raw_price_loader so that we can
# backshift dates.
self._calendar = self.raw_price_loader._calendar
self.adjustments_loader = adjustments_loader
def load_adjusted_array(self, columns, dates, assets, mask):
# load_adjusted_array is called with dates on which the user's algo
# will be shown data, which means we need to return the data that would
# be known at the start of each date. We assume that the latest data
# known on day N is the data from day (N - 1), so we shift all query
# dates back by a day.
start_date, end_date = _shift_dates(
self._calendar, dates[0], dates[-1], shift=1,
)
raw_arrays = self.raw_price_loader.load_raw_arrays(
columns,
start_date,
end_date,
assets,
)
adjustments = self.adjustments_loader.load_adjustments(
columns,
dates,
assets,
)
return [
adjusted_array(raw_array, mask, col_adjustments)
for raw_array, col_adjustments in zip(raw_arrays, adjustments)
]
def _shift_dates(dates, start_date, end_date, shift):
try:
start = dates.get_loc(start_date)
except KeyError:
if start_date < dates[0]:
raise NoFurtherDataError(
msg=(
"Pipeline Query requested data starting on {query_start}, "
"but first known date is {calendar_start}"
).format(
query_start=str(start_date),
calendar_start=str(dates[0]),
)
)
else:
raise ValueError("Query start %s not in calendar" % start_date)
# Make sure that shifting doesn't push us out of the calendar.
if start < shift:
raise NoFurtherDataError(
msg=(
"Pipeline Query requested data from {shift}"
" days before {query_start}, but first known date is only "
"{start} days earlier."
).format(shift=shift, query_start=start_date, start=start),
)
try:
end = dates.get_loc(end_date)
except KeyError:
if end_date > dates[-1]:
raise NoFurtherDataError(
msg=(
"Pipeline Query requesting data up to {query_end}, "
"but last known date is {calendar_end}"
).format(
query_end=end_date,
calendar_end=dates[-1],
)
)
else:
raise ValueError("Query end %s not in calendar" % end_date)
return dates[start - shift], dates[end - shift]