settings_window.py

from PyQt5.QtWidgets import QMainWindow, QMessageBox
from PyQt5.uic import loadUi
from detection_window import DetectionWindow


class SettingsWindow(QMainWindow):
    def __init__(self):
        super(SettingsWindow, self).__init__()
        loadUi("UI\settings_window.ui", self)
        self.detection_window = DetectionWindow()
        self.pushButton.clicked.connect(self.go_to_detection)

    def displayInfo(self):
        self.show()

    def go_to_detection(self):
        if self.detection_window.isVisible():
            print("Detection window is Already Open")

        else:
            self.detection_window.create_detection_instance()
            self.detection_window.start_detection()

    def closeEvent(self, event):
        if self.detection_window.isVisible():
            self.detection_window.detection.running = False
            self.detection_window.close()
            event.accept()