PySide2：AttributeError：'NoneType' object 没有属性'objectName'

Question

How can I fix this error:

Traceback (most recent call last):

File "", line 32, in run_setup_turn_table

AttributeError: 'NoneType' object has no attribute 'objectName'

from PySide2.QtCore import *
from PySide2.QtGui import *
from PySide2.QtWidgets import *
import sys

class mk_preview_UI(QWidget):
    def __init__(self):
        super(mk_preview_UI,self).__init__()
        
        self.UI()
        self.layout()
        self.show()
    def UI(self):
        self.setup_turnTable = QPushButton("Setup turn table")
        self.setup_turnTable.setObjectName("run_setup_btn")
        
    def layout(self):
        self.main_layout = QVBoxLayout()
        self.main_layout.addWidget(self.setup_turnTable)
        self.setLayout(self.main_layout)



class run_ui:
    def __init__(self):
        self.MainWindow = mk_preview_UI()
        self.MainWindow.setup_turnTable.clicked.connect(self.run_setup_turn_table)

    def run_setup_turn_table(self):
        run_button = self.MainWindow.sender()
        if run_button.objectName() == "run_setup_btn":
           print "run_setup_btn"       
        


if __name__ == "__main__":
    app = QApplication(sys.argv)
    MainWindow = run_ui()
    sys.exit(app.exec_())

Answer 1

Note: Seems a PySide2 bug.

If a QObject emits the signal and invokes the method of another QObject then sender() of the receiver object will return the emitter object. In your case MainWindow is not the receiver so the sender() will not return the object that emits the signal. A workaround is to make run_ui a QObject and since the run_setup_turn_table method belongs to it, then the sender() will return the button.

class run_ui(QObject):
    def __init__(self):
        super().__init__()
        self.MainWindow = mk_preview_UI()
        self.MainWindow.setup_turnTable.clicked.connect(self.run_setup_turn_table)

    def run_setup_turn_table(self):
        run_button = self.sender()
        if run_button.objectName() == "run_setup_btn":
            print("run_setup_btn")