使用 observables 创建任务 python 不起作用

Question

我想制作一个程序，您插入指向 web 的链接，它会抓取所有图像并使用 asyncio 下载它们并与 tkinter 通信，以便放置带有反应的图像列表。 我有一个基本的结构，但直到我按下按钮 7 次或多或少，它才起作用，我不知道为什么它不起作用。

from tkinter import *
from tkinter import messagebox
from PIL import ImageTk, Image
import asyncio
import os
import threading
import aiohttp
import requests
from bs4 import BeautifulSoup
from rx import create
import rx
import io
import base64
import sys

def main(async_loop):

    if sys.version_info[0] == 3 and sys.version_info[1] >= 8 and sys.platform.startswith('win'):
        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())

    async def get_urls(url):
            img_urls = []
            content = requests.get(url)
            soup = BeautifulSoup(content.text, 'html.parser')
            for img in soup.find_all('img'):
                if img is not None:
                    img_urls.append({'alt': img['alt'], 'src': img['src']})
            return img_urls


    class Printer(rx.core.Observer):
        def on_next(self, v):
            print(f'Recibido: {v["alt"]}')
            listbox.insert(END, v['alt'])

        def on_completed(self):
            print('Terminado')

    imgs_list=[]

    async def do_urls():
        print('do_urls')
        img_urls = await get_urls(entry.get())
        tasks = []
        def observer_img(o, s):
            print(img_urls)

            async def one_url(url):
                print(f'{url}')
                async with aiohttp.ClientSession() as session:
                    print(f'{url["src"]}')
                    print(f'session: {session}\n')
                    async with session.get(url['src']) as resp:
                        print(f'resp: {resp}\n')
                        if resp.status == 200:
                            print('oleeeeaaa')
                            try:
                                print('200 oleee')
                                imgs_list.append(base64.b64encode(await resp.read()))
                                o.on_next({'alt': url['alt'], 'img': imgs_list[-1]})
                            except OSError:
                                pass
                            except IOError:
                                pass
                            except:
                                pass

            tasks.append([asyncio.create_task(one_url(url)) for url in img_urls])
        await asyncio.gather(*tasks)
        create(observer_img).subscribe(Printer())
        #[asyncio.create_task(one_url(url)) for url in img_urls]

    def _asyncio_thread(async_loop):
        print('_asyncio_thread')
        async_loop.run_until_complete(do_urls())

    def do_tasks(async_loop):
        """ Button-Event-Handler starting the asyncio part. """
        print('do_task')
        threading.Thread(target=_asyncio_thread, args=(async_loop,)).start()

    def callback(event):
        selection = event.widget.curselection()
        if selection:
            index = selection[0]
            #image = Image.open(io.BytesIO(imgs_list[index]))
            image = ImageTk.PhotoImage(data=imgs_list[index])
            canvas.itemconfig(image_container, image=image)

    root = Tk()
    root.title = 'Descarga de imágenes'
    Label(text='URL a procesar:', font=('Arial', 12)).grid(pady=5, row=0, column=0)

    entry = Entry(width=40)
    entry.grid(padx=5, row=0 ,column=1)

    Button(text='Buscar', width=50, command= lambda:do_tasks(async_loop)).grid(padx=10, pady=10, column=0, row=1, columnspan=2)

    listbox = Listbox(width=70)
    listbox.grid(padx=10, pady=10, column=0, row=2, columnspan=2)

    canvas = Canvas(width=300, height=300)
    canvas.grid(row=2, column=1)
    image_container = canvas.create_image(20, 20, anchor=NW)
    listbox.bind("<<ListboxSelect>>", callback)

    root.mainloop()

if __name__ == '__main__':
    async_loop = asyncio.get_event_loop()
    main(async_loop)