text: import numpy as np 
  
  def stdeviation(risk_returns,Rebalancement_frequency):
  
          """
          Compute the standard deviation of the investment  
  
          Parameters
          ----------
          risk_returns : np.ndarray
          Rebalancement_frequency : np.float64
  
          Returns
          ----------
  
          float64, standard deviation 
  
          """
          stdev = np.std(risk_returns) * Rebalancement_frequency**.5
          return stdev