code: def __init__(self):
      if self.p.approach == "closeclose":
          self.pctdown = self.data.close / self.data.close(-1) - 1.0
      elif self.p.approach == "openclose":
          self.pctdown = self.data.close / self.data.open - 1.0
      elif self.p.approach == "highclose":
          self.pctdown = self.data.close / self.data.high - 1.0
      elif self.p.approach == "highlow":
          self.pctdown = self.data.low / self.data.high - 1.0
  
file_path: backtrader/samples/btfd/btfd.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import datetime
  import backtrader
label_desc: Use image node_id 1 to create a new St object from inherited base classes: bt with example: obj = St()