How to schedule a function to run every hour on Flask?

Question

I have a Flask web hosting with no access to cron command.

How can I execute some Python function every hour?

Answer 1

You could try using APScheduler's BackgroundScheduler to integrate interval job into your Flask app. Below is the example that uses blueprint and app factory (init.py) :

from datetime import datetime

# import BackgroundScheduler
from apscheduler.schedulers.background import BackgroundScheduler
from flask import Flask

from webapp.models.main import db 
from webapp.controllers.main import main_blueprint    

# define the job
def hello_job():
    print('Hello Job! The time is: %s' % datetime.now())

def create_app(object_name):
    app = Flask(__name__)
    app.config.from_object(object_name)
    db.init_app(app)
    app.register_blueprint(main_blueprint)
    # init BackgroundScheduler job
    scheduler = BackgroundScheduler()
    # in your case you could change seconds to hours
    scheduler.add_job(hello_job, trigger='interval', seconds=3)
    scheduler.start()

    try:
        # To keep the main thread alive
        return app
    except:
        # shutdown if app occurs except 
        scheduler.shutdown()

Hope it helps :)

Ref :

1. https://github.com/agronholm/apscheduler/blob/master/examples/schedulers/background.py