not responding in youtube downloader kivy app

Question

I wrote this program with Python:

import os
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from time import sleep
import pytube
import scrapetube
from pathlib import Path

save_addr = f"{os.environ['USERPROFILE']}\Downloads\Youtube DL"
print(save_addr)

layout = BoxLayout

def youtube_dl(video,addr):
        #yt = pytube.YouTube(f"{link.text}")
        #ys = yt.streams.get_highest_resolution()
        #ys.download()
        video = str(video.text)
        try:
            yt = pytube.YouTube(video)
            ys = yt.streams.get_highest_resolution()
            ys.download(output_path=addr)
        except pytube.exceptions.RegexMatchError:
            print('The Regex pattern did not return any matches for the video: {}'.format(video))          
        except pytube.exceptions.ExtractError:
            print('An extraction error occurred for the video: {}'.format(video))         
        except pytube.exceptions.VideoUnavailable:
            print('The following video is unavailable: {}'.format(video))

class cd:
    """Context manager for changing the current working directory"""
    def __init__(self, newPath):
        self.newPath = os.path.expanduser(newPath)

    def __enter__(self):
        self.savedPath = os.getcwd()
        os.chdir(self.newPath)

    def __exit__(self, etype, value, traceback):
        os.chdir(self.savedPath)


class MyGrid(layout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.orientation = "vertical"
        self.spacing = 20
        self.padding = [10, 10]
        self.cols = 1
        self.label = Label(text="Enter link of Video You Want to Download!")
        self.add_widget(self.label)
        self.link = TextInput(hint_text="Example: youtube.com/watch?v=MXDHK_MqRsk", multiline=False)
        self.add_widget(self.link)
        self.btn = Button(text="OK!")
        self.btn.bind(on_press=lambda x:self.callback())
        self.add_widget(self.btn)
        sleep(3)

    def callback(self):
        def dl(video,addr,DL=True):
            try:
                yt = pytube.YouTube(video)
                if DL:
                    ys = yt.streams.get_highest_resolution()
                    cd(addr)
                    ys.download(output_path=addr)
            except pytube.exceptions.RegexMatchError:
                print('The Regex pattern did not return any matches for the video: {}'.format(video))          
            except pytube.exceptions.ExtractError:
                print('An extraction error occurred for the video: {}'.format(video))         
            except pytube.exceptions.VideoUnavailable:
                print('The following video is unavailable: {}'.format(video))
            return yt
        video = str(self.link.text)
        title = str(dl(video,self.link,DL=False).title)
        self.label.text = f"Download : \"{title}\" , Save in:"
        self.link.text = f"{save_addr}"
        self.btn.text = "Download video!"
        self.btn.bind(on_press=lambda x:dl(video,self.link.text))

class MyKivy(App):
        def build(self):
            return MyGrid()

if __name__ == "__main__":
    MyKivy().run()

My problem is that when I put the video link to the program and click on download, when downloading the video from YouTube, the message not responding is displayed, but after the download is complete, the program returns to normal:

image of this error

What can I do to prevent the message not responding from being displayed?

Answer 1

To prevent this, you have to use multithreading, that means you can do multiple tasks simulatiously, that will prevent the UI from freezing because it will running in a thread that is not in the same thread that the downloader is running on. you will make a function to run the downloader in threading like this:

import threading
def run_thread(self,*args):
    thread_dl = thrading.Thread(target = self.downloader,args = (arg1,arg2,arg3))
    thread_dl.start()

you will edit this function to be the button on_press function