code: def __init__(self):
      nzd = NonZeroDifference(self.data0, self.data1)
  
      if self._crossup:
          before = nzd(-1) < 0.0  # data0 was below or at 0
          after = self.data0 > self.data1
      else:
          before = nzd(-1) > 0.0  # data0 was above or at 0
          after = self.data0 < self.data1
  
      self.lines.cross = And(before, after)
  
file_path: backtrader/backtrader/indicators/crossover.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from .None import Indicator, And
label_desc: Use image node_id 1 to create a new _CrossBase object from inherited base classes: Indicator with example: obj = _CrossBase()