code: def percent_b(data, period, upper_bb_std=2.0, lower_bb_std=2.0):
      
      lb = lower_bollinger_band(data, period, lower_bb_std)
      ub = upper_bollinger_band(data, period, upper_bb_std)
      percent_b = ((np.array(data) - lb) / (ub - lb)) * 100
      return percent_b
docs: %B.
  
      Formula:
      %B = ((data - lb) / (ub - lb)) * 100