readfile class in pyqt5 with QThread

reader.py

from PyQt5.QtCore import QThread, pyqtSignal

class FileReader(QThread):
    data_read = pyqtSignal(str)

    def __init__(self, filename):
        super().__init__()
        self.filename = filename

    def run(self):
        with open(self.filename, 'r', encoding='utf-8') as file:
            for line in file:
                self.data_read.emit(line.strip())
                
# use in another class :
# toolButton.clicked.connect(self.OnOpenFile)

class Main_Board_App(QMainWindow):
    def __init__(self):
        super(Main_Board_App, self).__init__()
    # reader from connect toolbutton
    def OnOpenFile(self):
        fileDial = QFileDialog(self)
        filePath, _ = fileDial.getOpenFileName(self, "Select Target Text File", "", "Text Files (*.txt)")
        if filePath:
            self.Line_Address_File.setText(filePath)
            self.Label_Massage.setText("Successfully Select File")
            self.index_openfile = True
            self.reader = FileReader(filePath)
            self.reader.data_read.connect(self.OnRead)
            self.reader.start()

        else:
            return None
  def OnRead(self, line):
      self.z += 1
      self.Log(f"ADDR : {line}")
      self.targetList.append(line)