Lately been reading about python concurrency realpython - python concurrency
My main focus asyncio so am fairly new.
The code block that performs asynchronous activities using asyncio and aiohttp runs fine when run it directly.
However when i add the code to my flask blueprint it raises this error:
RuntimeError: There is no current event loop in thread 'Thread-2'
For demonstration purposes i made a demo flask app. In case anyone wants to test it out.
main.py
from flask import Flask from my_blueprint import my_blueprint #Define flask app app = Flask(__name__) #load blueprints app.register_blueprint(my_blueprint,url_prefix='/demo') #start flask if __name__ == '__main__': app.run(debug=True) my_blueprint.py
from flask import Blueprint,request, jsonify,abort,make_response from flask import make_response import asyncio import time import aiohttp my_blueprint = Blueprint('my_blueprint', __name__) @my_blueprint.route('/',methods=['GET']) def home(): #code block async def download_site(session, url): async with session.get(url) as response: print("Read {0} from {1}".format(response.content_length, url)) async def download_all_sites(sites): async with aiohttp.ClientSession() as session: tasks = [] for url in sites: task = asyncio.ensure_future(download_site(session, url)) tasks.append(task) await asyncio.gather(*tasks, return_exceptions=True) sites = ["https://www.jython.org","http://olympus.realpython.org/dice"]*20 start_time = time.time() asyncio.get_event_loop().run_until_complete(download_all_sites(sites)) duration = time.time() - start_time return jsonify({"status":f"Downloaded {len(sites)} sites in {duration} seconds"}) #end of code block 
