input: Write a python function to calculate the Sharpe ratio given an array of daily returns.
  assert calculate_sharpe_ratio([0.023, 0.033, 0.085, -0.023, -0.011, 0.053, 0.032, 0.042, -0.031, 0.021]) == 1.1067299926406176
  assert calculate_sharpe_ratio([0.01, 0.02, 0.03, 0.04, 0.05]) == 2.82842712474619
  assert calculate_sharpe_ratio([-0.02, -0.01, 0.00, 0.01, 0.02]) == 1.5811388300841898
output: def calculate_sharpe_ratio(daily_returns):
      import numpy as np
      
      mean_return = np.mean(daily_returns)
      std_dev_return = np.std(daily_returns, ddof=1)
      
      sharpe_ratio = mean_return / std_dev_return
      
      return sharpe_ratio