Python:如果QlineEdit已填满，如何启用按钮

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QLineEdit, QPushButton
from PyQt5.QtCore import Qt

class MyWindow(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        self.setLayout(layout)

        self.line_edit = QLineEdit()
        self.line_edit.setPlaceholderText("请输入文本")
        layout.addWidget(self.line_edit)
        
        self.button = QPushButton("按钮")
        layout.addWidget(self.button)

    def check_text(self):
        if len(self.line_edit.text()) > 0:
            self.button.setEnabled(True)
        else:
            self.button.setEnabled(False)

        self.line_edit.textChanged.connect(self.check_text)

if __name__ == "__main__":
    app = QApplication([])
    window = MyWindow()
    window.show()
    app.exec_()