code: def get_daily_return(df, value_col_name="account_value"):
      df = deepcopy(df)
      df["daily_return"] = df[value_col_name].pct_change(1)
      df["date"] = pd.to_datetime(df["date"])
      df.set_index("date", inplace=True, drop=True)
      df.index = df.index.tz_localize("UTC")
      return pd.Series(df["daily_return"], index=df.index)
  
imports: from __future__ import annotations
  import copy
  import datetime
  from copy import deepcopy
  import matplotlib.dates
  import matplotlib.pyplot
  import numpy
  import pandas
  import pyfolio
  from pyfolio import timeseries
  from finrl import config
  from finrl.meta.data_processors.func import date2str
  from finrl.meta.data_processors.func import str2date
  from finrl.meta.preprocessor.yahoodownloader import YahooDownloader
label_desc: Use image node_id 1 for calling a global function with example usage: get_daily_return(df, value_col_name) and returns: pd