Files
catalyst/zipline/utils/api_support.py
T

66 lines
1.9 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.
from functools import wraps
import zipline.api
import threading
context = threading.local()
def get_algo_instance():
return getattr(context, 'algorithm', None)
def set_algo_instance(algo):
context.algorithm = algo
class ZiplineAPI(object):
"""
Context manager for making an algorithm instance available to zipline API
functions within a scoped block.
"""
def __init__(self, algo_instance):
self.algo_instance = algo_instance
def __enter__(self):
"""
Set the given algo instance, storing any previously-existing instance.
"""
self.old_algo_instance = get_algo_instance()
set_algo_instance(self.algo_instance)
def __exit__(self, _type, _value, _tb):
"""
Restore the algo instance stored in __enter__.
"""
set_algo_instance(self.old_algo_instance)
def api_method(f):
# Decorator that adds the decorated class method as a callable
# function (wrapped) to zipline.api
@wraps(f)
def wrapped(*args, **kwargs):
# Get the instance and call the method
return getattr(get_algo_instance(), f.__name__)(*args, **kwargs)
# Add functor to zipline.api
setattr(zipline.api, f.__name__, wrapped)
zipline.api.__all__.append(f.__name__)
f.is_api_method = True
return f