code: def smooth(df, window_len=11, window="hanning"):
      
      if isinstance(df, pd.Series):
          new_df = _smooth(df, window_len=window_len, window=window)
      else:
          new_df = df.apply(_smooth, window_len=window_len, window=window)
      return new_df
docs: Smooth the data using a window with requested size.