code: def symmetry_looking(x, param):
      
      if not isinstance(x, (np.ndarray, pd.Series)):
          x = np.asarray(x)
      mean_median_difference = np.abs(np.mean(x) - np.median(x))
      max_min_difference = np.max(x) - np.min(x)
      return [("r_{}".format(r["r"]), mean_median_difference < (r["r"] * max_min_difference))
              for r in param]
docs: Boolean variable denoting if the distribution of x *looks symmetric*. This is the case if
  
      .. math::
  
          | mean(X)-median(X)| < r * (max(X)-min(X))
  
      :param x: the time series to calculate the feature of
      :type x: numpy.ndarray
      :param r: the percentage of the range to compare with
      :type r: float
      :return: the value of this feature
      :return type: bool