GreenClock is a time-based task scheduler using gevent
With GreenClock, you can: Schedule a task to run every X seconds, daily, weekly, monthly, or at certain times (such as application startup).
GreenClock launches a green thread per task. Therefore every task will be executed in a concurrent manner, without blocking each other.
This module is currently under development.
- A simple to use API for scheduling jobs.
- Lightweight (depending on gevent only)
- Works with Python 2.7+
- Support the following scheduling scenarios:
+ run every X seconds
+ run every hour at specified minute and second
+ run at specified time (hour:minute:second) every day
+ more to come
This library depends on gevent 1.0 RC2
$ pip install cython -e git://github.com/surfly/gevent.git@1.0rc2#egg=gevent
To install GreenClock from pip:
$ pip install greenclock
You can also install it into your Python application directory
$ pip install --install-option="--prefix=/path/to/python/app" greenclock
To install GreenClock from source:
$ git clone git@github.com:pcdinh/greenclock.git
$ python setup.py install
import greenclock
from datetime import datetime
import time
def func_1():
print('Calling func_1() at ' + str(datetime.now()))
time.sleep(2)
print('Ended call to func_1() at ' + str(datetime.now()))
def func_2():
print('Calling func_2() at ' + str(datetime.now()))
time.sleep(2)
print('Ended call to func_2() at ' + str(datetime.now()))
if __name__ == "__main__":
scheduler = greenclock.Scheduler(logger_name='task_scheduler')
scheduler.schedule('task_1', greenclock.every_second(4), func_1)
scheduler.schedule('task_2', greenclock.every_second(1), func_2)
# Run hourly task at 41:00 every day
scheduler.schedule('task_3', greenclock.every_hour(minute=41, second=0), func_3)
# Run daily task at 12:35:00
scheduler.schedule('task_2', greenclock.every_hour(hour=12, minute=35, second=0), func_2)
# To start the scheduled tasks immediately, specify 'once' for `start_at`
# Other values:
# * `next_minute`: Wait until the first seconds of the next minute to run
# * `next_hour`: Wait until the first seconds of the next hour to run
# * `tomorrow`: Wait until the first seconds of tomorrow to run
scheduler.run_forever(start_at='once')
Basically to schedule a periodic task or job, you need to specify the following parameters:
+ Task name: `task_1`
+ A timer that let the scheduler know how to run a periodic task
# run the task for every 4 seconds
greenclock.every_second(4)
# run the task every day at 01:10:00
greenclock.every_hour(hour=1, minute=10, second=0)
+ A function or callable object
+ Optional parameters to the above function or callable object
scheduler.schedule('task_1', greenclock.every_second(1), func_1, param1, param2, named_param=2)
Scheduler
object can run a separate process which never exits if you want it to
scheduler.run_forever(start_at='once')