cron-validator 1.0.8
Unix cron implementation by Python
License: MIT
Keywords: cron,python,cron expression validator,cron expression iterator,cron scheduler

# Cron Validator

[![Build Status](https://travis-ci.org/vcoder4c/cron-validator.svg?branch=master)](https://travis-ci.org/vcoder4c/cron-validator)
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### **Features**

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

### **Install**

```shell script
pip install cron-validator
```

### **Run Tests**

**1. Install test requirements**

```shell script
pip install -r requirements/test.txt
```

**2. Run tests (with coverage if wished)**

```shell script
pytest --cov=. test/
```

### Sample

**1. Validate unix cron expression**

```python
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**

```python
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**

```python
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**

```python
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.")
```

**5. Use extended cron rules based on AWS EventBridge rules** (from v1.0.6)

The cron validator supports partially extended rules based on the Amazon EvenBridge rule set. [More info.](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-rule-schedule.html#eb-cron-expressions)

Currently we support:
- 'L' for day of the month and day of the week
- 'W' for day of the week.

```python
from cron_validator import CronValidator
from cron_validator.util import str_to_datetime
from cron_validator.regexes import Version

dt_str = '2023-04-28 1:00'
dt = str_to_datetime(dt_str)

assert CronValidator.match_datetime("* * * * 30W", dt, version=Version.EB)
assert CronValidator.match_datetime("* * * * 5L", dt, version=Version.EB)

dt_str = "2022-02-28 1:00"
dt = str_to_datetime(dt_str)
assert CronValidator.match_datetime("* * L * *", dt, version=Version.EB)
```

### License

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