# Copyright 2020 The TensorTrade Authors.
#
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#
# Unless required by applicable law or agreed to in writing, software
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and

from abc import abstractmethod

import numpy as np

from gym.spaces import Space

[docs]class Observer(Component, TimeIndexed):
"""A component to generate an observation at each step of an episode.
"""

registered_name = "observer"

@property
@abstractmethod
def observation_space(self) -> Space:
"""The observation space of the TradingEnv. (Space, read-only)
"""
raise NotImplementedError()

[docs]    @abstractmethod
def observe(self, env: 'TradingEnv') -> np.array:
"""Gets the observation at the current step of an episode

Parameters
----------
np.array