class_docstr: Extends the Bollinger Bands with a Percentage line
code: def __init__(self):
      super(BollingerBandsPct, self).__init__()
      self.l.pctb = (self.data - self.l.bot) / (self.l.top - self.l.bot)
  
file_path: backtrader/backtrader/indicators/bollinger.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from .None import Indicator, MovAv, StdDev
label_desc: Use image node_id 1 to create a new BollingerBandsPct object from inherited base classes: BollingerBands with example: obj = BollingerBandsPct()