Crontable

A lightweight Python scheduler that unifies two task types in a single loop:

• DateTask — one-shot tasks triggered at a specific datetime, loaded from a semicolon-delimited CSV file
• CronTask — repeating tasks driven by standard 5-field cron expressions (or friendly @aliases), loaded from a crontab-style text file

Comes with a CLI entry-point and an optional tkinter GUI (crontable-gui).

Installation

pip install crontable

Requires Python ≥ 3.10. The only runtime dependency is croniter.

Quick start

Programmatic usage

from datetime import datetime, timedelta
from crontable import Scheduler, SubprocessExecutor, DateTask, CronTask

executor = SubprocessExecutor()
scheduler = Scheduler(executor=executor, interval=30.0)

scheduler.add_tasks([
    DateTask(
        scheduled_at=datetime.now() + timedelta(minutes=5),
        action="echo 'hello in 5 minutes'",
        name="greeting",
    ),
    CronTask(
        cron_expr="0 9 * * 1-5",
        action="python C:/scripts/daily_report.py",
        name="weekday_report",
    ),
])

try:
    scheduler.run()
except KeyboardInterrupt:
    scheduler.stop()

From a CSV file

DATE;NAME;COMMAND
01/01/2027 09:00;morning_report;echo "Good morning"
15/06/2027 14:30;backup;python C:\scripts\backup.py

from crontable import FileSource, Scheduler, SubprocessExecutor

source = FileSource("tasks.csv")
scheduler = Scheduler(executor=SubprocessExecutor(), interval=60.0)
scheduler.add_tasks(source.load())
scheduler.run()

From a crontab file

# Every weekday at 9 am
0 9 * * 1-5   python C:\scripts\report.py
# French alias — every Monday at midnight
@lundi        echo "Bonne semaine"

from crontable import FileSource, Scheduler, SubprocessExecutor

source = FileSource("jobs.txt")
scheduler = Scheduler(executor=SubprocessExecutor(), interval=60.0)
scheduler.add_tasks(source.load())
scheduler.run()

Hot-reload on file change

Pass the source to the scheduler and set reload_on_change=True. Every tick, the scheduler checks source.has_changed() and atomically swaps in source.load() when the file is touched. A failing parse (half-saved edit, invalid syntax) is logged and the previous task list is kept.

source = FileSource("jobs.txt")
scheduler = Scheduler(
    executor=SubprocessExecutor(),
    interval=5.0,
    source=source,
    reload_on_change=True,
)
scheduler.add_tasks(source.load())
scheduler.run()

See examples/ for more runnable patterns.

CLI

# Programmatic demo
crontable

# Load from file (auto-detects CSV vs crontab by extension)
crontable tasks.csv
crontable crontab.txt

GUI

crontable-gui

Features: file browser, configurable polling interval, live task list with right-click "Run now", color-coded log, hot-reload on file change, persistent config.

Build a standalone Windows .exe:

scripts\build_exe.bat

Supported cron aliases

Path aliases in commands

Development

pip install -e ".[dev]"
pytest