customButton

from PySide2.QtWidgets import QPushButton, QWidget, QApplication, QVBoxLayout
from PySide2.QtCore import Signal
import sys

class Window(QWidget):
    def __init__(self):
        super(Window, self).__init__()
        mainlayout = QVBoxLayout(self)

        button = MyButton("Test string")
        button.clickAction.connect(self.buttonAction) # catch our signal
        mainlayout.addWidget(button)

    def buttonAction(self, buttonText): # function gets the signal string by default
        print(buttonText)


class MyButton(QPushButton):
    clickAction = Signal(str) # signal prepared for button text

    def __init__(self, buttonText):
        super(MyButton, self).__init__()
        self.setText(buttonText)

        self.clicked.connect(self.emmitMySignal)

    def emmitMySignal(self):
        self.clickAction.emit(self.text()) # emit signal with text

app = QApplication(sys.argv)
win = Window()
win.show()
app.exec_()