code: def _retrieveRegions(self):
      
      self.sensors = []
      self.coarseSensors = []
      self.locationInputs = []
      self.L4Columns = []
      self.L2Columns = []
      self.L5Columns = []
      self.L6Columns = []
  
      for i in xrange(self.numColumns):
        self.sensors.append(
          self.network.regions["sensorInput_" + str(i)].getSelf()
        )
        self.coarseSensors.append(
          self.network.regions["coarseSensorInput_" + str(i)].getSelf()
        )
        self.locationInputs.append(
          self.network.regions["locationInput_" + str(i)].getSelf()
        )
        self.L4Columns.append(
          self.network.regions["L4Column_" + str(i)].getSelf()
        )
        self.L2Columns.append(
          self.network.regions["L2Column_" + str(i)].getSelf()
        )
        self.L5Columns.append(
          self.network.regions["L5Column_" + str(i)].getSelf()
        )
        self.L6Columns.append(
          self.network.regions["L6Column_" + str(i)].getSelf()
        )
docs: Retrieve and store Python region instances for each column