docstr: Calculate Sharpe ratio based on validation results
docstr_tok: ["Calculate","Sharpe","ratio","based","on","validation","results"]
code: def get_validation_sharpe(iteration, model_name):
      """Calculate Sharpe ratio based on validation results"""
      df_total_value = pd.read_csv(
          f"results/account_value_validation_{model_name}_{iteration}.csv"
      )
      # If the agent did not make any transaction
      if df_total_value["daily_return"].var() == 0:
          if df_total_value["daily_return"].mean() > 0:
              return np.inf
          else:
              return 0.0
      else:
          return (
              (4**0.5)
              * df_total_value["daily_return"].mean()
              / df_total_value["daily_return"].std()
          )
  
imports: from __future__ import annotations
  import time
  import numpy
  import pandas
  from stable_baselines3 import A2C
  from stable_baselines3 import DDPG
  from stable_baselines3 import PPO
  from stable_baselines3 import SAC
  from stable_baselines3 import TD3
  from stable_baselines3.common.callbacks import BaseCallback
  from stable_baselines3.common.noise import NormalActionNoise
  from stable_baselines3.common.noise import OrnsteinUhlenbeckActionNoise
  from stable_baselines3.common.vec_env import DummyVecEnv
  from finrl import config
  from finrl.meta.env_stock_trading.env_stocktrading import StockTradingEnv
  from finrl.meta.preprocessor.preprocessors import data_split
label_desc: Use image node_id 3 for calling the DRLEnsembleAgent obj's underlying member method code with example usage: obj.get_validation_sharpe(iteration, model_name) and returns: unknown, np, int