croniter
croniter provides iteration for datetime object with cron like format
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Description
Introduction
============
DISCLAIMER
============
**UNMAINTAINED/ABANDONED CODE / DO NOT USE**
Due to the new EU Cyber Resilience Act (as European Union), even if it was implied because there was no more activity, this repository is now explicitly declared unmaintained.
The content does not meet the new regulatory requirements and therefore cannot be deployed or distributed, especially in a European context.
This repository now remains online ONLY for public archiving, documentation and education purposes and we ask everyone to respect this.
As stated, the maintainers stopped development and therefore all support some time ago, and make this declaration on December 15, 2024.
We may also unpublish soon (as in the following monthes) any published ressources tied to this project (pypi, the repositories, ...).
So, please don't rely on it after March 15, 2025 and adapt whatever project which used this code.
.. contents::
croniter provides iteration for the datetime object with a cron like format.
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\___|_| \___/|_| |_|_|\__\___|_|
Website: https://github.com/kiorky/croniter
Build Badge
===========
.. image:: https://github.com/kiorky/croniter/actions/workflows/cicd.yml/badge.svg
:target: https://github.com/kiorky/croniter/actions/workflows/cicd.yml
Usage
============
A simple example::
>>> from croniter import croniter
>>> from datetime import datetime
>>> base = datetime(2010, 1, 25, 4, 46)
>>> iter = croniter('*/5 * * * *', base) # every 5 minutes
>>> print(iter.get_next(datetime)) # 2010-01-25 04:50:00
>>> print(iter.get_next(datetime)) # 2010-01-25 04:55:00
>>> print(iter.get_next(datetime)) # 2010-01-25 05:00:00
>>>
>>> iter = croniter('2 4 * * mon,fri', base) # 04:02 on every Monday and Friday
>>> print(iter.get_next(datetime)) # 2010-01-26 04:02:00
>>> print(iter.get_next(datetime)) # 2010-01-30 04:02:00
>>> print(iter.get_next(datetime)) # 2010-02-02 04:02:00
>>>
>>> iter = croniter('2 4 1 * wed', base) # 04:02 on every Wednesday OR on 1st day of month
>>> print(iter.get_next(datetime)) # 2010-01-27 04:02:00
>>> print(iter.get_next(datetime)) # 2010-02-01 04:02:00
>>> print(iter.get_next(datetime)) # 2010-02-03 04:02:00
>>>
>>> iter = croniter('2 4 1 * wed', base, day_or=False) # 04:02 on every 1st day of the month if it is a Wednesday
>>> print(iter.get_next(datetime)) # 2010-09-01 04:02:00
>>> print(iter.get_next(datetime)) # 2010-12-01 04:02:00
>>> print(iter.get_next(datetime)) # 2011-06-01 04:02:00
>>>
>>> iter = croniter('0 0 * * sat#1,sun#2', base) # 1st Saturday, and 2nd Sunday of the month
>>> print(iter.get_next(datetime)) # 2010-02-06 00:00:00
>>>
>>> iter = croniter('0 0 * * 5#3,L5', base) # 3rd and last Friday of the month
>>> print(iter.get_next(datetime)) # 2010-01-29 00:00:00
>>> print(iter.get_next(datetime)) # 2010-02-19 00:00:00
All you need to know is how to use the constructor and the ``get_next``
method, the signature of these methods are listed below::
>>> def __init__(self, cron_format, start_time=time.time(), day_or=True)
croniter iterates along with ``cron_format`` from ``start_time``.
``cron_format`` is **min hour day month day_of_week**, you can refer to
http://en.wikipedia.org/wiki/Cron for more details. The ``day_or``
switch is used to control how croniter handles **day** and **day_of_week**
entries. Default option is the cron behaviour, which connects those
values using **OR**. If the switch is set to False, the values are connected
using **AND**. This behaves like fcron and enables you to e.g. define a job that
executes each 2nd Friday of a month by setting the days of month and the
weekday.
::
>>> def get_next(self, ret_type=float)
get_next calculates the next value according to the cron expression and
returns an object of type ``ret_type``. ``ret_type`` should be a ``float`` or a
``datetime`` object.
Supported added for ``get_prev`` method. (>= 0.2.0)::
>>> base = datetime(2010, 8, 25)
>>> itr = croniter('0 0 1 * *', base)
>>> print(itr.get_prev(datetime)) # 2010-08-01 00:00:00
>>> print(itr.get_prev(datetime)) # 2010-07-01 00:00:00
>>> print(itr.get_prev(datetime)) # 2010-06-01 00:00:00
You can validate your crons using ``is_valid`` class method. (>= 0.3.18)::
>>> croniter.is_valid('0 0 1 * *') # True
>>> croniter.is_valid('0 wrong_value 1 * *') # False
About DST
=========
Be sure to init your croniter instance with a TZ aware datetime for this to work!
Example using pytz::
>>> import pytz
>>> tz = pytz.timezone("Europe/Paris")
>>> local_date = tz.localize(datetime(2017, 3, 26))
>>> val = croniter('0 0 * * *', local_date).get_next(datetime)
Example using python_dateutil::
>>> import dateutil.tz
>>> tz = dateutil.tz.gettz('Asia/Tokyo')
>>> local_date = datetime(2017, 3, 26, tzinfo=tz)
>>> val = croniter('0 0 * * *', local_date).get_next(datetime)
Example using python built in module::
>>> from datetime import datetime, timezone
>>> local_date = datetime(2017, 3, 26, tzinfo=timezone.utc)
>>> val = croniter('0 0 * * *', local_date).get_next(datetime)
About second repeats
=====================
Croniter is able to do second repetition crontabs form and by default seconds are the 6th field::
>>> base = datetime(2012, 4, 6, 13, 26, 10)
>>> itr = croniter('* * * * * 15,25', base)
>>> itr.get_next(datetime) # 4/6 13:26:15
>>> itr.get_next(datetime) # 4/6 13:26:25
>>> itr.get_next(datetime) # 4/6 13:27:15
You can also note that this expression will repeat every second from the start datetime.::
>>> croniter('* * * * * *', local_date).get_next(datetime)
You can also use seconds as first field::
>>> itr = croniter('15,25 * * * * *', base, second_at_beginning=True)
About year
===========
Croniter also support year field.
Year presents at the seventh field, which is after second repetition.
The range of year field is from 1970 to 2099.
To ignore second repetition, simply set second to ``0`` or any other const::
>>> base = datetime(2012, 4, 6, 2, 6, 59)
>>> itr = croniter('0 0 1 1 * 0 2020/2', base)
>>> itr.get_next(datetime) # 2020 1/1 0:0:0
>>> itr.get_next(datetime) # 2022 1/1 0:0:0
>>> itr.get_next(datetime) # 2024 1/1 0:0:0
Support for start_time shifts
==============================
See https://github.com/kiorky/croniter/pull/76,
You can set start_time=, then expand_from_start_time=True for your generations to be computed from start_time instead of calendar days::
>>> from pprint import pprint
>>> iter = croniter('0 0 */7 * *', start_time=datetime(2024, 7, 11), expand_from_start_time=True);pprint([iter.get_next(datetime) for a in range(10)])
[datetime.datetime(2024, 7, 18, 0, 0),
datetime.datetime(2024, 7, 25, 0, 0),
datetime.datetime(2024, 8, 4, 0, 0),
datetime.datetime(2024, 8, 11, 0, 0),
datetime.datetime(2024, 8, 18, 0, 0),
datetime.datetime(2024, 8, 25, 0, 0),
datetime.datetime(2024, 9, 4, 0, 0),
datetime.datetime(2024, 9, 11, 0, 0),
datetime.datetime(2024, 9, 18, 0, 0),
datetime.datetime(2024, 9, 25, 0, 0)]
>>> # INSTEAD OF THE DEFAULT BEHAVIOR:
>>> iter = croniter('0 0 */7 * *', start_time=datetime(2024, 7, 11), expand_from_start_time=False);pprint([iter.get_next(datetime) for a in range(10)])
[datetime.datetime(2024, 7, 15, 0, 0),
datetime.datetime(2024, 7, 22, 0, 0),
datetime.datetime(2024, 7, 29, 0, 0),
datetime.datetime(2024, 8, 1, 0, 0),
datetime.datetime(2024, 8, 8, 0, 0),
datetime.datetime(2024, 8, 15, 0, 0),
datetime.datetime(2024, 8, 22, 0, 0),
datetime.datetime(2024, 8, 29, 0, 0),
datetime.datetime(2024, 9, 1, 0, 0),
datetime.datetime(2024, 9, 8, 0, 0)]
Testing if a date matches a crontab
===================================
Test for a match with (>=0.3.32)::
>>> croniter.match("0 0 * * *", datetime(2019, 1, 14, 0, 0, 0, 0))
True
>>> croniter.match("0 0 * * *", datetime(2019, 1, 14, 0, 2, 0, 0))
False
>>>
>>> croniter.match("2 4 1 * wed", datetime(2019, 1, 1, 4, 2, 0, 0)) # 04:02 on every Wednesday OR on 1st day of month
True
>>> croniter.match("2 4 1 * wed", datetime(2019, 1, 1, 4, 2, 0, 0), day_or=False) # 04:02 on every 1st day of the month if it is a Wednesday
False
Testing if a crontab matches in datetime range
==============================================
Test for a match_range with (>=2.0.3)::
>>> croniter.match_range("0 0 * * *", datetime(2019, 1, 13, 0, 59, 0, 0), datetime(2019, 1, 14, 0, 1, 0, 0))
True
>>> croniter.match_range("0 0 * * *", datetime(2019, 1, 13, 0, 1, 0, 0), datetime(2019, 1, 13, 0, 59, 0, 0))
False
>>> croniter.match_range("2 4 1 * wed", datetime(2019, 1, 1, 3, 2, 0, 0), datetime(2019, 1, 1, 5, 1, 0, 0))
# 04:02 on every Wednesday OR on 1st day of month
True
>>> croniter.match_range("2 4 1 * wed", datetime(2019, 1, 1, 3, 2, 0, 0), datetime(2019, 1, 1, 5, 2, 0, 0), day_or=False)
# 04:02 on every 1st day of the month if it is a Wednesday
False
Gaps between date matches
=========================
For performance reasons, croniter limits the amount of CPU cycles spent attempting to find the next match.
Starting in v0.3.35, this behavior is configurable via the ``max_years_between_matches`` parameter, and the default window has been increased from 1 year to 50 years.
The defaults should be fine for many use cases.
Applications that evaluate multiple cron expressions or handle cron expressions from untrusted sources or end-users should use this parameter.
Iterating over sparse cron expressions can result in increased CPU consumption or a raised ``CroniterBadDateErr