Data Update
------------------

This program creates a simple PyQt5 widget that updates the current time in real-time. The widget displays the current time, updating every second.

.. code-block:: python
    :caption: scripts/PYQT5/03_thread/03_background_data_update/main.py

    # -*- coding: utf-8 -*-

    import sys
    from PyQt5.QtWidgets import QApplication, QLabel, QVBoxLayout, QWidget
    from PyQt5.QtCore import QTimer, QDateTime

    class TimeUpdateWidget(QWidget):
        def __init__(self):
            super(TimeUpdateWidget, self).__init__()

            self.initUI()

            # QTimer 객체 생성
            self.timer = QTimer(self)
            self.timer.timeout.connect(self.update_time)  # 타이머 시간이 끝날 때마다 update_time 함수 호출
            self.timer.start(1000)  # 1초마다 타이머 시작

        def initUI(self):
            self.label = QLabel(self)
            layout = QVBoxLayout()
            layout.addWidget(self.label)
            self.setLayout(layout)
            

        def update_time(self):
            current_time = QDateTime.currentDateTime().toString('yyyy-MM-dd hh:mm:ss')
            self.label.setText(current_time)

    if __name__ == "__main__":
        app = QApplication([])
        mainWindow = TimeUpdateWidget()
        mainWindow.show()
        app.exec_()

- ``QTimer``: This class emits a signal at a given time interval. In this context, it emits the ``timeout`` signal every second, triggering the ``update_time`` function.

- ``update_time`` function: This function fetches the current time and displays it on the label.