在QTableWidget中选择行时启用/禁用QPushButton

from PyQt5.QtWidgets import QApplication, QMainWindow, QTableWidget, QPushButton, QVBoxLayout, QWidget

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.table_widget = QTableWidget()
        self.button = QPushButton("按钮")
        self.button.setEnabled(False)

        layout = QVBoxLayout()
        layout.addWidget(self.table_widget)
        layout.addWidget(self.button)

        widget = QWidget()
        widget.setLayout(layout)
        self.setCentralWidget(widget)

        self.table_widget.itemSelectionChanged.connect(self.on_selection_changed)

    def on_selection_changed(self):
        selected_rows = self.table_widget.selectedItems()
        if selected_rows:
            self.button.setEnabled(True)
        else:
            self.button.setEnabled(False)

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