class_docstr: Bollinger Bands
  
  https://school.stockcharts.com/doku.php?id=technical_indicators:bollinger_bands
  
  Args:
      close(pandas.Series): dataset 'Close' column.
      window(int): n period.
      window_dev(int): n factor standard deviation
      fillna(bool): if True, fill nan values.
class_docstr_tok: ["Bollinger","Bands","https",":","\/\/school.stockcharts.com\/doku.php","?","id=technical_indicators",":","bollinger_bands","Args",":","close","(","pandas.Series",")",":","dataset","'Close","'","column",".","window","(","int",")",":","n","period",".","window_dev","(","int",")",":","n","factor","standard","deviation","fillna","(","bool",")",":","if","True",",","fill","nan","values","."]
code: def __init__(
      self,
      close: pd.Series,
      window: int = 20,
      window_dev: int = 2,
      fillna: bool = False,
  ):
      self._close = close
      self._window = window
      self._window_dev = window_dev
      self._fillna = fillna
      self._run()
  
imports: import numpy
  import pandas
  from ta.utils import IndicatorMixin
label_desc: Use image node_id 1 to create a new BollingerBands object from inherited base classes: IndicatorMixin with example: obj = BollingerBands(close, window, window_dev, fillna)