pyqt/basic/signals_and_slots_3.py

import sys
from random import choice

from PyQt5.QtWidgets import QMainWindow, QPushButton, QApplication

window_titles = [
    "My App", "My App", "Still My App", "Still My App", "What on earth",
    "What on earth", "This is surprising", "This is surprising",
    "Something went wrong"
]


class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        self.n_times_clicked = 0

        self.setWindowTitle("My App")

        self.button = QPushButton("Press Me!")
        self.button.clicked.connect(self.the_button_was_clicked)

        self.windowTitleChanged.connect(self.the_window_tile_changed)

        # Set the central widget of the window
        self.setCentralWidget(self.button)

    def the_button_was_clicked(self):
        print("Clicked.")
        new_window_tile = choice(window_titles)
        print("Setting title: %s" % new_window_tile)
        self.setWindowTitle(new_window_tile)

    def the_window_tile_changed(self, window_tile):
        print("Window title changed: %s" % window_tile)

        if window_tile == "Something went wrong":
            self.button.setDisabled(True)


app = QApplication(sys.argv)

window = MainWindow()
window.show()

app.exec_()