old_contents: # coding=utf-8
  # Copyright 2018 The TF-Agents Authors.
  #
  # 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.
  
  """Policy implementation that generates greedy actions from another policy."""
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import gin
  import tensorflow as tf  # pylint: disable=g-explicit-tensorflow-version-import
  import tensorflow_probability as tfp
  from tf_agents.policies import tf_policy
  from tf_agents.trajectories import policy_step
  
  
  # TODO(b/131405384): Remove this once Deterministic does casting internally.
  class DeterministicWithLogProb(tfp.distributions.Deterministic):
    """Thin wrapper around Deterministic that supports taking log_prob."""
  
    def _log_prob(self, x):
      """Takes log-probs by casting to tf.float32 instead of self.dtype."""
      return tf.math.log(tf.cast(self.prob(x), dtype=tf.float32))
  
  
  @gin.configurable(module='tf_agents', blacklist=['policy'])
  class GreedyPolicy(tf_policy.TFPolicy):
    """Returns greedy samples of a given policy."""
  
    def __init__(self, policy, name=None):
      """Builds a greedy TFPolicy wrapping the given policy.
  
      Args:
        policy: A policy implementing the tf_policy.TFPolicy interface.
        name: The name of this policy. All variables in this module will fall
          under that name. Defaults to the class name.
      """
      super(GreedyPolicy, self).__init__(
          policy.time_step_spec,
          policy.action_spec,
          policy.policy_state_spec,
          policy.info_spec,
          emit_log_probability=policy.emit_log_probability,
          name=name)
      self._wrapped_policy = policy
  
    @property
    def wrapped_policy(self):
      return self._wrapped_policy
  
    def _variables(self):
      return self._wrapped_policy.variables()
  
    def _distribution(self, time_step, policy_state):
      def dist_fn(dist):
        try:
          greedy_action = dist.mode()
        except NotImplementedError:
          raise ValueError("Your network's distribution does not implement mode "
                           "making it incompatible with a greedy policy.")
  
        return DeterministicWithLogProb(loc=greedy_action)
  
      distribution_step = self._wrapped_policy.distribution(
          time_step, policy_state)
      return policy_step.PolicyStep(
          tf.nest.map_structure(dist_fn, distribution_step.action),
          distribution_step.state, distribution_step.info)
  
new_contents: # coding=utf-8
  # Copyright 2018 The TF-Agents Authors.
  #
  # 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.
  
  """Policy implementation that generates greedy actions from another policy."""
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import gin
  import tensorflow as tf  # pylint: disable=g-explicit-tensorflow-version-import
  import tensorflow_probability as tfp
  from tf_agents.policies import tf_policy
  from tf_agents.trajectories import policy_step
  
  
  # TODO(b/131405384): Remove this once Deterministic does casting internally.
  @tfp.experimental.register_composite
  class DeterministicWithLogProb(tfp.distributions.Deterministic):
    """Thin wrapper around Deterministic that supports taking log_prob."""
  
    def _log_prob(self, x):
      """Takes log-probs by casting to tf.float32 instead of self.dtype."""
      return tf.math.log(tf.cast(self.prob(x), dtype=tf.float32))
  
  
  @gin.configurable(module='tf_agents', blacklist=['policy'])
  class GreedyPolicy(tf_policy.TFPolicy):
    """Returns greedy samples of a given policy."""
  
    def __init__(self, policy, name=None):
      """Builds a greedy TFPolicy wrapping the given policy.
  
      Args:
        policy: A policy implementing the tf_policy.TFPolicy interface.
        name: The name of this policy. All variables in this module will fall
          under that name. Defaults to the class name.
      """
      super(GreedyPolicy, self).__init__(
          policy.time_step_spec,
          policy.action_spec,
          policy.policy_state_spec,
          policy.info_spec,
          emit_log_probability=policy.emit_log_probability,
          name=name)
      self._wrapped_policy = policy
  
    @property
    def wrapped_policy(self):
      return self._wrapped_policy
  
    def _variables(self):
      return self._wrapped_policy.variables()
  
    def _distribution(self, time_step, policy_state):
      def dist_fn(dist):
        try:
          greedy_action = dist.mode()
        except NotImplementedError:
          raise ValueError("Your network's distribution does not implement mode "
                           "making it incompatible with a greedy policy.")
  
        return DeterministicWithLogProb(loc=greedy_action)
  
      distribution_step = self._wrapped_policy.distribution(
          time_step, policy_state)
      return policy_step.PolicyStep(
          tf.nest.map_structure(dist_fn, distribution_step.action),
          distribution_step.state, distribution_step.info)
  
subject: Fix distribution regsitration in greedy policy.