APScheduler is a Python timer task framework based on Quartz.Tasks based on dates, fixed intervals, and crontab types are provided and can be persisted.
Online documentation: https://apscheduler.readthedocs.io/en/latest/userguide.html

1. Install APScheduler

pip install apscheduler

2. Basic concepts

APScheduler has four components:
1. Trigger triggers:
Triggers contain scheduling logic.Each job has its own triggers that determine when the next task will run.Triggers are completely stateless except for the initial configuration.
There are three built-in trigger s:
(1) date: triggered at a specific point in time
(2) interval: fixed interval trigger
(3) cron: triggered periodically at a specific time
2. Task Store job stores: Store tasks in memory (default MemoryJobStore) or in a database.
3. Executor executors: An executor submits a task to a thread pool or a process pool to run, and when the task completes, the executor tells the scheduler to trigger the corresponding event.
4. Scheduler schedulers: Run by creating a dispatcher instance with the above three components as parameters
Select the appropriate components for your development needs. Here are the different scheduler components:
BlockingScheduler Blocking Scheduler: For programs that run only schedulers.
BackgroundScheduler Background Scheduler: For non-blocking scenarios, the scheduler runs independently in the background.
AsyncIO Scheduler AsyncIO Scheduler, suitable for applications that use AsyncIO.
The GeventScheduler Gevent Scheduler is designed for applications that pass through Gevent.
The Tornado Scheduler Tornado Scheduler is suitable for building Tornado applications.
TwistedScheduler Twisted Scheduler, suitable for building Twisted applications.
QtScheduler Qt Scheduler, suitable for building Qt applications.

3. Steps for use
1. Create a new scheduler
2. Add Scheduling Tasks
3. Run Scheduling Tasks

4. Examples of use

1. Trigger date

Triggers at a specific point in time and executes only once.The parameters are as follows:

Example use:

from datetime import datetime
from datetime import date
from apscheduler.schedulers.blocking import BlockingScheduler

def job(text):    
    print(text)

scheduler = BlockingScheduler()
# In 2019-8-30 Run once job Method
scheduler.add_job(job, 'date', run_date=date(2019, 8, 30), args=['text1'])
# In 2019-8-30 01:00:00 Run once job Method
scheduler.add_job(job, 'date', run_date=datetime(2019, 8, 30, 1, 0, 0), args=['text2'])
# In 2019-8-30 01:00:01 Run once job Method
scheduler.add_job(job, 'date', run_date='2019-8-30 01:00:00', args=['text3'])

scheduler.start()

2. Trigger interval

Fixed interval trigger.The parameters are as follows:

Example use:

import time
from apscheduler.schedulers.blocking import BlockingScheduler

def job(text):    
    t = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(time.time()))
    print('{} --- {}'.format(text, t))

scheduler = BlockingScheduler()
# Run every minute job Method
scheduler.add_job(job, 'interval', minutes=1, args=['job1'])
# In 2019-08-29 22:15:00 To 2019-08-29 22:17:00 Period, run every 1 minute 30 seconds job Method
scheduler.add_job(job, 'interval', minutes=1, seconds = 30, start_date='2019-08-29 22:15:00', end_date='2019-08-29 22:17:00', args=['job2'])

scheduler.start()

'''
//Run result:
job2 --- 2019-08-29 22:15:00
job1 --- 2019-08-29 22:15:46
job2 --- 2019-08-29 22:16:30
job1 --- 2019-08-29 22:16:46
job1 --- 2019-08-29 22:17:46
...Remaining omitted...
'''

3. Trigger cron

Triggers periodically at a specific time.The parameters are as follows:

These parameters support arithmetic expressions in the following formats:

Example use:

import time
from apscheduler.schedulers.blocking import BlockingScheduler

def job(text):    
    t = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(time.time()))
    print('{} --- {}'.format(text, t))

scheduler = BlockingScheduler()
# Run every minute at 22 o'clock a day job Method
scheduler.add_job(job, 'cron', hour=22, minute='*/1', args=['job1'])
# Run once a day at 22 and 23:25 job Method
scheduler.add_job(job, 'cron', hour='22-23', minute='25', args=['job2'])

scheduler.start()

'''
//Run result:
job1 --- 2019-08-29 22:25:00
job2 --- 2019-08-29 22:25:00
job1 --- 2019-08-29 22:26:00
job1 --- 2019-08-29 22:27:00
...Remaining omitted...
'''

4. Add method by decorator scheduled_job()

There are two ways to add tasks: