关闭对话框前添加验证

Question

在单击确定按钮时，在接受对话框之前，我需要检查是否有任何lineEdits为空。我试图覆盖这样的buttonBox接受的插槽：

#self.buttonBox.accepted.connect(Dialog.accept)
self.buttonBox.rejected.connect(Dialog.reject)
QtCore.QMetaObject.connectSlotsByName(Dialog)

self.buttonBox.accepted.connect(self.validate)

def validate(self, Dialog):
    if (self.lineEdit.text() == '' or self.lineEdit_2.text() == '' or self.lineEdit_3.text() == '' or self.lineEdit_4.text() == '' or self.lineEdit_5.text() == ''):
        QtWidgets.QMessageBox.about(QtWidgets.QMessageBox(), 'Error', 'All fields are mandatory!')
    else:
        Dialog.accept()

但是我得到了错误：

TypeError: validate() missing 1 required positional argument: 'Dialog'