Scheduler

0.8.11 verified Sat May 09 auth: no python

A simple in-process Python scheduler library with asyncio, threading, and timezone support. Current version 0.8.11 supports Python >=3.10. Released as needed.

pip install scheduler

Common errors

error AttributeError: module 'scheduler' has no attribute 'Scheduler' ↓

cause Importing the wrong path (e.g., from scheduler.scheduler import Scheduler) in older versions or using a stale installation.

fix

Use 'from scheduler import Scheduler' (top-level).

error AttributeError: 'Scheduler' object has no attribute 'schedule' ↓

cause Calling the old method name 'schedule' which was renamed to 'cyclic' in v0.8.0.

fix

Replace 'scheduler.schedule(interval, job)' with 'scheduler.cyclic(interval, job)'.

error ImportError: cannot import name 'AsyncIOScheduler' from 'scheduler' ↓

cause Trying to import the async scheduler directly from the top-level package, but it is in a submodule.

fix

Use 'from scheduler.asyncio import Scheduler as AsyncIOScheduler'.

Warnings

gotcha The library requires manual calling of exec_jobs() in a loop; it does not run automatically. Failing to call exec_jobs() in a loop will result in no tasks executing. ↓

fix Run scheduler.exec_jobs() inside a while loop or use the provided async/threading wrappers.

gotcha Timing changes between exec_jobs() calls are skipped if the next execution time is in the past. Tasks are not caught up; they wait for the next scheduled time. ↓

fix Ensure exec_jobs() is called frequently enough to avoid missing scheduled times, or adjust for missed executions manually.

deprecated The method 'schedule' was renamed to 'cyclic' in version 0.8.0. Using 'schedule' raises AttributeError. ↓

fix Use scheduler.cyclic(interval, job) instead of scheduler.schedule(interval, job).

breaking Support for Python <3.10 dropped in version 0.8.0. Installing on older Python versions will fail. ↓

fix Upgrade to Python >=3.10 or pin to scheduler==0.7.3.

Imports

Scheduler
wrong
```
from scheduler.scheduler import Scheduler
```
correct
```
from scheduler import Scheduler
```
Top-level import only; submodule import breaks compatibility.

AsyncIOScheduler

wrong

from scheduler import AsyncIOScheduler

correct

from scheduler.asyncio import Scheduler as AsyncIOScheduler

Async scheduler lives in a submodule import asyncio.Scheduler

ThreadingScheduler

wrong

from scheduler import ThreadingScheduler

correct

from scheduler.threading import Scheduler as ThreadingScheduler

Threading scheduler lives in a submodule import threading.Scheduler

Quickstart

Basic usage: create a Scheduler, schedule a cyclic task, then repeatedly call exec_jobs() in a loop.

from scheduler import Scheduler
import time

scheduler = Scheduler()

def my_task():
    print("Task executed")

# Schedule every 5 seconds
scheduler.cyclic(5, my_task)

# Run for 10 seconds
start = time.time()
while time.time() - start < 10:
    scheduler.exec_jobs()
    time.sleep(0.1)