new_contents: # -*- coding: utf-8 -*-
  #
  # Copyright 2017 Ricequant, 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 bcolz
  
  
  class SimpleFactorStore(object):
      def __init__(self, f):
          self._table = bcolz.open(f, 'r')
          self._index = self._table.attrs['line_map']
  
      def get_factors(self, order_book_id):
          try:
              s, e = self._index[order_book_id]
              return self._table[s:e]
          except KeyError:
              return None
  
subject: add simple factor store