import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *

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

    def initUI(self):
        self.setWindowTitle('SWH Academy Window.')
        self.setGeometry(200, 200, 360, 100)

        self.label = QLabel("", self)
        self.label.move(120, 20)
        self.label.resize(150, 30)

        self.lineEdit = QLineEdit("", self)
        self.lineEdit.move(20, 50)
        self.lineEdit.textChanged.connect(self.lineEditChanged)

        button2 = QPushButton("지우기", self)
        button2.move(130, 50)
        button2.clicked.connect(self.button2Clicked)
        
        button3 = QPushButton("종료", self)
        button3.move(240, 50)
        button3.clicked.connect(QCoreApplication.instance().quit)

    def lineEditChanged(self):
        self.label.setText(self.lineEdit.text())

    def button2Clicked(self):
        self.label.clear()
        self.lineEdit.clear()
        
if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MyWindow()
    window.show()
    sys.exit(app.exec_())