How to perform periodic task with Flask in Python

user_252556 0
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I've been using Flask to provide a simple web API for my k8055 USB interface board; fairly standard getters and putters, and Flask really made my life a lot easier.

But I want to be able to register changes of state as / near when whey happen.

For instance, if I have a button connected to the board, I can poll the api for that particular port. But if I wanted to have the outputs directly reflect the outputs, whether or not someone was talking to the api, I would have something like this.

while True:
    board.read()
    board.digital_outputs = board.digital_inputs
    board.read()
    time.sleep(1)

And every second, the outputs would be updated to match the inputs.

Is there any way to do this kind of thing under Flask? I've done similar things in Twisted before but Flask is too handy for this particular application to give up on it just yet...

Thanks.

flask wsgi api web-services python
4 Answers

For some reason, Antony's code wasn't working for me. I didn't get any error messages or anything, but the test_job function wouldn't run.

I was able to get it working by installing Flask-APScheduler and then using the following code, which is a blend of Antony's code and the example from this Techcoil article.

from flask import Flask
from flask_apscheduler import APScheduler

app = Flask(__name__)

def test_job():
    print('I am working...')

scheduler = APScheduler()
scheduler.init_app(app)
scheduler.start()
scheduler.add_job(id='test-job', func=test_job, trigger='interval', seconds=1)
user_11085050
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