code: def sortino_ratio(returns, required_return=0, period=DAILY):
      
  
      return ep.sortino_ratio(returns, required_return=required_return)
docs: Determines the Sortino ratio of a strategy.
  
      Parameters
      ----------
      returns : pd.Series or pd.DataFrame
          Daily returns of the strategy, noncumulative.
          - See full explanation in :func:`~pyfolio.timeseries.cum_returns`.
      required_return: float / series
          minimum acceptable return
      period : str, optional
          Defines the periodicity of the 'returns' data for purposes of
          annualizing. Can be 'monthly', 'weekly', or 'daily'.
          - Defaults to 'daily'.
  
      Returns
      -------
      depends on input type
      series ==> float
      DataFrame ==> np.array
  
          Annualized Sortino ratio.