innateessence / pycron

cron in python-land

pycron

What is this

• Just a fun project for supporting cron-ish syntax for Python threads
• In other words, this is a (cron-ish) task scheduler available in pure Python

Why does this exist

• Because I wanted cron-like behavior for pure Python threads without pulling in celery
• Because sometimes I find I want something highly niche and custom, that is not supported by the major packages such as celery
• It's a good foundation for a project I may or may not take on in the future
• "What I cannot create, I do not understand" — Richard Feynman.

What this is not

• A replacement for celery.
• Production-grade software

Quickstart

example usage:

from pycron import PyCron

def my_python_func_to_schedule(foo: str):
    # some interesting code here
    print(f"foo is: {foo}")
    with open("my_py_log", 'a') as f:
        f.write(f"foo is {foo}")

def my_bash_task_to_schedule(foo: str):
    # some system calls to make
    os.system(f"echo foo is {foo}")
    os.system(f"echo foo is {foo} >> my_bash_log")

pycron = PyCron()
pycron.add('* * * * *', my_python_func_to_schedule, "foobar")
pycron.add('* * * * *', my_bash_task_to_schedule, "buzz")
pycron.start()
# Now both functions will run under their own thread whenever
# the system clock hits 00 seconds
# just like how you'd expect a cronjob to behave

Testing

• Running the test cases: python test.py
• Interactive testing / debugging: python pycron.py

Improvements

• Adding a system unit such as a systemd service would probably be a good idea