v2_714573.py

from multiprocessing import Process, Queue
from queue import Empty
from PyQt5.QtWidgets import *
from PyQt5.QtCore import QTimer


def calc(q):
    q.put(sum(i**i for i in range(10000)))


def reline_helper(s):
    import re
    return '\n'.join(filter(None, re.split(r"(.{300})",s)))


if __name__ == '__main__':
    app = QApplication([])
    window = QWidget()
    layout = QVBoxLayout()
    btnCalc = QPushButton('Do Calc')
    lblCalc = QLabel('idle')
    is_calculating = [False]
    q = Queue()


    @btnCalc.clicked.connect
    def on_button_clicked():
        if is_calculating[0]:
            return
        is_calculating[0] = True
        lblCalc.setText("generating process...")
        p = Process(target=calc, args=(q,))
        lblCalc.setText("calculating...")
        p.start()
        timer = QTimer(window)


        @timer.timeout.connect
        def timers():
            try:
                print("polls")
                result = q.get(block=False)
                print(result)
                lblCalc.setText(reline_helper(str(result)))
                p.join()
                timer.stop()
                is_calculating[0] = False
            except Empty:
                pass


        timer.start(1000)


    layout.addWidget(btnCalc)
    layout.addWidget(lblCalc)
    window.setLayout(layout)
    window.show()
    app.exec_()