import sys
from PyQt5.QtWidgets import *

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
        
    def initUI(self):
        self.setWindowTitle("SWH")

        button = QPushButton("눌러봐", self)
        button.move(50, 30)
        button.clicked.connect(self.click)

    def click(self):
        QMessageBox.about(self, "메세지 박스", "눌렀어요.")

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MyWindow()
    window.show()
    app.exec_()