import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton
app = QApplication(sys.argv)
MainWindow = QMainWindow()
MainWindow.resize(300,300)
btn = QPushButton('test',MainWindow)
btn.setObjectName('Button1')
def ButtonsOnclick():
    global MainWindow
    print('Click')
    print(MainWindow.sender().objectName())
btn.clicked.connect(ButtonsOnclick)

MainWindow.show()
sys.exit(app.exec_())