old_contents: from .base import *
  from .contextfree import *
  from .linear import *
  from .logistic import *
  from .offline import *
  
new_contents: from obp.policy.base import BaseContextFreePolicy
  from obp.policy.base import BaseContextualPolicy
  from obp.policy.base import BaseOfflinePolicyLearner
  from obp.policy.contextfree import EpsilonGreedy
  from obp.policy.contextfree import Random
  from obp.policy.contextfree import BernoulliTS
  from obp.policy.linear import LinEpsilonGreedy
  from obp.policy.linear import LinUCB
  from obp.policy.linear import LinTS
  from obp.policy.logistic import LogisticEpsilonGreedy
  from obp.policy.logistic import LogisticUCB
  from obp.policy.logistic import LogisticTS
  from obp.policy.logistic import MiniBatchLogisticRegression
  from obp.policy.offline import IPWLearner
  
  
  __all__ = [
      "BaseContextFreePolicy",
      "BaseContextualPolicy",
      "BaseOfflinePolicyLearner",
      "EpsilonGreedy",
      "Random",
      "BernoulliTS",
      "LinEpsilonGreedy",
      "LinUCB",
      "LinTS",
      "LogisticEpsilonGreedy",
      "LogisticUCB",
      "LogisticTS",
      "MiniBatchLogisticRegression",
      "IPWLearner"
  ]
  
subject: fix flake8 error for ope/__init__.py