How to make stop button active in PyQT5 application?

Question

Python

I'm trying to make a simple GUI for a website parser. Here is the design code:

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'gui.ui'
#
# Created by: PyQt5 UI code generator 5.11.2
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(638, 350)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        MainWindow.setMinimumSize(QtCore.QSize(638, 350))
        MainWindow.setMaximumSize(QtCore.QSize(638, 350))
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.start_btn = QtWidgets.QPushButton(self.centralwidget)
        self.start_btn.setGeometry(QtCore.QRect(10, 100, 191, 71))
        font = QtGui.QFont()
        font.setPointSize(20)
        self.start_btn.setFont(font)
        self.start_btn.setObjectName("start_btn")
        self.open_btn = QtWidgets.QPushButton(self.centralwidget)
        self.open_btn.setGeometry(QtCore.QRect(10, 10, 191, 71))
        font = QtGui.QFont()
        font.setPointSize(15)
        self.open_btn.setFont(font)
        self.open_btn.setObjectName("open_btn")
        self.listWidget = QtWidgets.QListWidget(self.centralwidget)
        self.listWidget.setGeometry(QtCore.QRect(220, 10, 411, 311))
        self.listWidget.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.listWidget.setEditTriggers(QtWidgets.QAbstractItemView.DoubleClicked|QtWidgets.QAbstractItemView.SelectedClicked)
        self.listWidget.setAlternatingRowColors(True)
        self.listWidget.setObjectName("listWidget")
        self.progressBar = QtWidgets.QProgressBar(self.centralwidget)
        self.progressBar.setEnabled(False)
        self.progressBar.setGeometry(QtCore.QRect(10, 280, 191, 41))
        self.progressBar.setProperty("value", 0)
        self.progressBar.setObjectName("progressBar")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setEnabled(False)
        self.pushButton.setGeometry(QtCore.QRect(10, 180, 191, 71))
        font = QtGui.QFont()
        font.setPointSize(20)
        self.pushButton.setFont(font)
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "firmenabc scraper"))
        self.start_btn.setText(_translate("MainWindow", "Start"))
        self.open_btn.setText(_translate("MainWindow", "Open File"))
        self.pushButton.setText(_translate("MainWindow", "Stop"))

And here is the parser code:

import requests, csv, sys, os
import gui
from bs4 import BeautifulSoup as bs
from PyQt5 import QtWidgets
from PyQt5.QtCore import Qt
from multiprocessing import Pool


class ScrapeApp(QtWidgets.QMainWindow, gui.Ui_MainWindow):
    def __init__(self):
        # Это здесь нужно для доступа к переменным, методам
        # и т.д. в файле gui_table.py
        super().__init__()
        self.setupUi(self)  # Это нужно для инициализации нашего дизайна
        self.open_btn.clicked.connect(self.open_file)
        self.start_btn.clicked.connect(self.scrape)
        self.start_btn.clicked.connect(self.stop)
        self.statusBar().showMessage('Ready')
        self.completed = 0

    def open_file(self):
        filename = QtWidgets.QFileDialog.getOpenFileName(self, 'Open .txt file')[0]
        if filename and filename.split('.')[-1] == 'txt':
            with open(filename, 'rb') as file:
                content = file.read().splitlines()
            self.statusbar.showMessage('File opened successfully!')
            self.listWidget.clear()
            for word in content:
                item = QtWidgets.QListWidgetItem(word.decode('iso-8859-14'))
                item.setFlags(Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable)
                self.listWidget.addItem(item)
        else:
            self.statusbar.showMessage('Wrong file extension. Please, choose .txt file')

    def stop(self):
        self.stop()

    def scrape(self):
        self.progressBar.setEnabled(True)
        self.start_btn.setDisabled(True)
        self.pushButton.setEnabled(True)
        while self.completed <= 100:
            if self.listWidget.count() == 0:
                self.open_file()
            self.statusbar.showMessage('Started scraping process...')
            with open('result.csv', 'w', newline='') as file:
                writer = csv.writer(file)
                header = ['Name', 'Street', 'Zip Code', 'City', 'Region', 'Email', 'Phone', 'Website']
                writer.writerow(header)
            rows = []
            for index in range(self.listWidget.count()):
                rows.append(self.listWidget.item(index).text())
            print('rows:', rows)
            for keyword in rows:
                soup = get_soup(keyword, '')
                max_pages = soup.find('ol', {'class': 'pagination'}).find_all('li')[-1].get_text().strip()
                print('max pages:', max_pages)
                links = get_links(soup)
                with Pool(10) as p:
                    p.map(make_all, links)
                    if int(max_pages) > 1:
                        si = 50
                        for page in range(2, int(max_pages)):
                            new_soup = get_soup(keyword, si)
                            new_links = get_links(new_soup)
                            with Pool(10) as pp:
                                pp.map(make_all, new_links)
                            si += 50
                self.completed += 100 / len(rows)
                self.progressBar.setValue(self.completed)
            self.statusbar.showMessage('Scraping process finished successfully!')
            self.stop()


def get_soup(word, si):
    r = requests.get('https://www.firmenabc.at/result.aspx?what={}&where=&exact=false&inTitleOnly=false&l=&si={}'
                     '0&iid=&sid=-1&did=&cc='.format(word, si))
    soup = bs(r.text, 'lxml')
    return soup


def get_links(sp):  # extract companies links from current page's soup
    links = [a.get('href') for a in sp.find_all('a', {'itemprop': 'url'})]
    return links


def scrape_items(link):  # extract required data of each company
    soup = bs(requests.get(link).text, 'lxml')
    name = soup.find('div', {'itemprop': 'name'}).get_text().strip()
    street = soup.find('span', {'itemprop': 'streetAddress'}).get_text().strip()
    zip_code = soup.find('span', {'itemprop': 'postalCode'}).get_text().strip()
    city = soup.find('span', {'itemprop': 'addressLocality'}).get_text().strip()
    try:
        region = soup.find('meta', {'itemprop': 'addressRegion'}).get('content')
    except AttributeError:
        try:
            region = soup.find('meta', {'property': 'og:region'}).get('content')
        except AttributeError:
            try:
                region = soup.find('meta', {'itemprop': 'og:region'}).get('content')
            except AttributeError:
                region = city
    try:
        email = soup.find('meta', {'property': 'og:email'}).get('content')
    except AttributeError:
        try:
            email = soup.find('a', {'itemprop': 'email'}).get_text().strip()
        except AttributeError:
            email = ''
    try:
        phone = soup.find('meta', {'property': 'og:phonenumber'}).get('content')
    except AttributeError:
        try:
            phone = soup.find('span', {'itemprop': 'telephone'}).get_text().strip()
        except AttributeError:
            phone = ''
    try:
        website = soup.find('div', {'class': 'contact-data'}).find('a', {'itemprop': 'url'}).get('href')
    except AttributeError:
        website = ''
    value = [name, street, zip_code, city, region, email, phone, website]
    print(value)
    return value


def save(lst):
    with open('result.csv', 'a', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(lst)


def make_all(link):
    data = scrape_items(link)
    save(data)


def main():
    app = QtWidgets.QApplication(sys.argv)
    window = ScrapeApp()
    window.show()
    app.exec_()


if __name__ == '__main__':
    main()

Actually the question is what - when I click on the Start, the main window is blocked and I can not click on the Stop button. How to make it active? Tell me where to read, please. Well, if you show an example, I will be grateful too .... Well, the next question is how to stop the execution of the parser with the Stop button?
PS: as input the program receives a simple text file with keywords like
"
tischlerei
möbel
bau
garten
"

Answer 1

self.start_btn.clicked.connect(self.scrape)
self.start_btn.clicked.connect(self.stop)
one event - 2 reactions.
The activity/inactivity of widgets is set by the setEnabled(bool) method.
Inactive element does not send signals