code: def price_oscillator(data, short_period, long_period):
      
      catch_errors.check_for_period_error(data, short_period)
      catch_errors.check_for_period_error(data, long_period)
  
      ema_short = ema(data, short_period)
      ema_long = ema(data, long_period)
  
      po = ((ema_short - ema_long) / ema_long) * 100
      return po
docs: Price Oscillator.
  
      Formula:
      (short EMA - long EMA / long EMA) * 100