docstr: Use value model of self.model to predict value of obs
          
docstr_tok: ["Use","value","model","of","self.model","to","predict","value","of","obs"]
code: def value_predict(self, obs):
      """Use value model of self.model to predict value of obs"""
      return self.model.value(obs)
  
file_path: PARL/parl/algorithms/fluid/ppo.py
imports: import warnings
  import numpy
  from copy import deepcopy
  from paddle import fluid
  from parl.core.fluid import layers
  from parl.core.fluid.algorithm import Algorithm
label_desc: Use image node_id 7 for calling the PPO obj's underlying member method code with example usage: obj.value_predict(obs) and returns: self