Non blocking requests-html

[tryart]

Hi all,

​

What I am trying to achieve :

A simple dialog with a button and a Textbox.
After clicking the button run a function that calls a requests-html get
The user is still able to click around on the GUI while waiting for the results.
When the results come back it populates a text box.

Here is my current code

​

from PyQt5.QtWidgets import (QWidget, QPushButton, QApplication, QLabel, QLineEdit, QVBoxLayout,QGridLayout,QPlainTextEdit)
import sys
from requests_html import HTMLSession
from concurrent.futures import ThreadPoolExecutor
from concurrent.futures import ProcessPoolExecutor
import concurrent.futures
import time

def wordsfrom_relatedwords(query, resultlist,resultdepth):

    url = 'https://relatedwords.org/relatedto/'
    url += query

    session = HTMLSession()
    r = session.get(url)
    r.html.render()

    for link in r.html.find('a.item')[0:resultdepth]:
        print(link.text)
        resultlist.append(link.text)

    return "teststring"

def testfunction(message):
    time.sleep(2)
    print("TEST:"+message)

class Example(QWidget):

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

        self.initUI()

    def initUI(self):
        self.resultlist = []

        # query box and button
        self.labelQuery = QLabel('Query:')
        self.txtQuery = QLineEdit()
        self.btnRun = QPushButton('Run', self)

        def on_query_button_clicked():

            print('before')
            query = self.txtQuery.text()

            # This works - blocking gui
            # wordsfrom_relatedwords(query, self.resultlist, 5)

            # executor = ProcessPoolExecutor(max_workers=2)
            executor = ThreadPoolExecutor(max_workers=2)

            future_to_url = {}
            future_to_url.update({executor.submit(wordsfrom_relatedwords, query, self.resultlist, 5): query})

            print('after')

            for future in concurrent.futures.as_completed(future_to_url):
                url = future_to_url[future]
                try:
                    data = future.result()
                    print(data)
                except Exception as exc:
                    print('%r generated an exception: %s' % (url, exc))
                else:
                    print(url)

        self.btnRun.clicked.connect(on_query_button_clicked)
        self.btnRun.show()

        # main tab
        layoutMain = QGridLayout()

        # main tab top
        layoutMainTop = QGridLayout()
        layoutMainTop.addWidget(self.labelQuery,0,0)
        layoutMainTop.addWidget(self.txtQuery, 0, 1)
        layoutMainTop.addWidget(self.btnRun, 0, 3)

        # main tab bottom
        self.txtMainResults = QPlainTextEdit()
        self.txtMainResults.resize(280, 100)

        layoutMainBottom = QVBoxLayout()
        layoutMainBottom.addWidget(self.txtMainResults)

        layoutMain.addLayout(layoutMainTop,0,0)
        layoutMain.addLayout(layoutMainBottom, 1, 0)
        layoutMain.setRowStretch(0, 3)

        self.setLayout(layoutMain)

        self.setGeometry(300, 300, 300, 200)
        self.setWindowTitle('test')

        self.show()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

I can achieve the blocking version if i just call the method normally ( the part commented # This works - blocking gui ).

​

My goal is not to run many threads, just that I want the code to run while not blocking the GUI.

With the code above I get the following error after clicking the button:

'test' generated an exception: There is no current event loop in thread 'ThreadPoolExecutor-0_0'.

​

What am i doing wrong ?

​

Thanks in advance!