Cron Descriptor

Warnings

• breaking The parsing of cron expressions moved from `ExpressionDescriptor.get_description()` to the `ExpressionDescriptor` constructor in version 1.3. This means parsing exceptions are now thrown when creating an `ExpressionDescriptor` instance, not when calling `get_description()`. Update your exception handling logic accordingly.
  Fix: Wrap `ExpressionDescriptor()` instantiation in a `try...except` block to catch parsing errors.
• breaking The `throw_exception_on_parse_error` option was removed in version 1.3. The library now always throws an exception if a cron expression cannot be parsed, effectively behaving as if `throw_exception_on_parse_error=True`.
  Fix: Ensure all cron expressions passed to the descriptor are valid, or implement `try...except` blocks around `ExpressionDescriptor` instantiation.
• breaking In version 2.0.3, the `Options` constructor parameters (`locale_code`, `use_24hour_time_format`) now explicitly override auto-detected system locale settings. If you previously relied on auto-detection and then set these in `Options` objects, their behavior might change to reflect the explicit settings.
  Fix: Review `Options` constructor usage to ensure desired locale and time format behavior. Explicitly set `locale_code` if you need a specific localization, or omit it to rely on auto-detection.
• breaking Custom exceptions within the library were renamed from `*Exception` (e.g., `CronDescriptorException`) to `*Error` (e.g., `CronDescriptorError`) in version 2.0.3. Update `except` clauses to catch the new exception names.
  Fix: Update `except` blocks to catch the new exception names (e.g., `CronDescriptorError` instead of `CronDescriptorException`). Consult the source for specific exception names if needed.
• gotcha Using both Day of Month and Day of Week fields with explicit values (e.g., `1 1 1 1 1`) can be ambiguous in cron. While this library generally handles `?` to signify 'no specific value' for one of them, be aware that other cron parsers or environments might have different interpretations or stricter validation.
  Fix: Use `?` in either the Day of Month or Day of Week field if you intend for one to be ignored. For example, `0 0 1 * ?` (1st of every month, any day of week) or `0 0 ? * MON` (every Monday, any day of month).

Install

• pip install cron-descriptor Install stable version

Imports

• get_description

  from cron_descriptor import get_description

  Direct import from the top-level package is the current standard. Older versions might have had deeper imports, or some examples might mistakenly show a submodule.
• ExpressionDescriptor

  from cron_descriptor import ExpressionDescriptor

• Options

  from cron_descriptor import Options

• CasingTypeEnum

  from cron_descriptor import CasingTypeEnum

• DescriptionTypeEnum

  from cron_descriptor import DescriptionTypeEnum

Quickstart

Demonstrates basic usage with the `get_description` function and the `ExpressionDescriptor` class, including how to customize output with `Options` for casing, 24-hour format, and locale.

from cron_descriptor import get_description, ExpressionDescriptor, Options, CasingTypeEnum, DescriptionTypeEnum

# Simple usage
print(get_description("* 2 3 * *"))

# Using ExpressionDescriptor class
descriptor_instance = ExpressionDescriptor("* 2 3 * *")
print(str(descriptor_instance))

# Advanced usage with Options
options = Options()
options.casing_type = CasingTypeEnum.Sentence
options.use_24hour_time_format = True
options.locale_code = 'en' # Explicitly set locale for consistency

advanced_descriptor = ExpressionDescriptor("*/10 * * * *", options)
print(advanced_descriptor.get_description(DescriptionTypeEnum.FULL))