Cron Validator

Features

• Validate unix cron expression
• Match unit cron expression with specific datetime
• Generate match datetime between two datetime
• Schedule tasks

Install

pip install cron-validator

Run Tests

1. Install test requirements

pip install -r requirements/test.txt

2. Run tests (with coverage if wished)

pytest --cov=. test/

Sample

1. Validate unix cron expression

from cron_validator import CronValidator

assert CronValidator.parse('* * * * *') is not None # valid
assert CronValidator.parse('*/3 * * * *') is not None # valid
assert CronValidator.parse('*/61 * * * *') is None # invalid

2. Match unit cron expression with specific datetime

from cron_validator import CronValidator
from cron_validator.util import str_to_datetime

dt_str = '2019-04-23 1:00'
dt = str_to_datetime(dt_str)

assert CronValidator.match_datetime("* * * * *", dt)
assert CronValidator.match_datetime("* * * 4 *", dt)
assert CronValidator.match_datetime("* * * 5 *", dt) is False
assert CronValidator.match_datetime("* * * 1-5 *", dt)
assert CronValidator.match_datetime("* * * 1-3 *", dt) is False
assert CronValidator.match_datetime("* * * 1/5 *", dt) is False
assert CronValidator.match_datetime("* * * * *", dt)
assert CronValidator.match_datetime("0 * * * *", dt)
assert CronValidator.match_datetime("0-30 * * * *", dt)
assert CronValidator.match_datetime("0/30 * * * *", dt)

3. Generate match datetime between two datetime

from cron_validator import CronValidator
from cron_validator.util import str_to_datetime


from_str = '2019-04-22 00:00'
to_str = '2019-04-23 23:59'

for dt in CronValidator.get_execution_time("0 0 * * *", 
from_dt=str_to_datetime(from_str), to_dt=str_to_datetime(to_str)):
    print(dt)

# Output:
# 2019-04-22 00:00:00+00:00
# 2019-04-23 00:00:00+00:00

4. Use scheduler for repetitive task

from cron_validator import CronScheduler

cron_string = "*/1 * * * *"
scheduler = CronScheduler(cron_string)

while True:
    if scheduler.time_for_execution():
        # Get's called every full minute (excluding first iteration)
        print("Now is the next scheduled time.")

License

This project is licensed under the MIT License - see the LICENSE.txt file for details