pyiron_base.utils.error module

Utility functions used in pyiron. In order to be accessible from anywhere in pyiron, they must remain free of any imports from pyiron!

class pyiron_base.utils.error.ImportAlarm(message=None)

Bases: object

In many places we have try/except loops around imports. This class is meant to accompany that code so that users get an early warning when they instantiate a job that won’t work when run.

Example:

>>> try:
...     from mystery_package import Enigma, Puzzle, Conundrum
...     import_alarm = ImportAlarm()
>>> except ImportError:
>>>     import_alarm = ImportAlarm(
...         "MysteryJob relies on mystery_package, but this was unavailable. Please ensure your python environment "
...         "has access to mystery_package, e.g. with `conda install -c conda-forge mystery_package`"
...     )
...
>>> class MysteryJob(GenericJob):
...     @import_alarm
...     def __init__(self, project, job_name)
...         super().__init__()
...         self.riddles = [Enigma(), Puzzle(), Conundrum()]

This class is also a context manager that can be used as a short-cut, like this:

>>> with ImportAlarm("MysteryJob relies on mystery_package, but this was unavailable.") as import_alarm:
...     import mystery_package

If you do not use import_alarm as a decorator, but only to get a consistent warning message, call warn_if_failed() after the with statement.

>>> import_alarm.warn_if_failed()
warn_if_failed()

Print warning message if import has failed. In case you are not using ImportAlarm as a decorator you can call this method manually to trigger the warning.

wrapper(function)
pyiron_base.utils.error.retry(func: Callable[[], T], error: Type[Exception] | Tuple[Type[Exception], ...], msg: str, at_most: int | None = None, delay: float = 1.0, delay_factor: float = 1.0) → T

Try to call func until it no longer raises error.

Any other exception besides error is still raised.

Parameters:

  • func (callable) – function to call, should take no arguments

  • error (Exception or tuple thereof) – any exceptions to be caught

  • msg (str) – messing to be written to the log if error occurs.

  • at_most (int, optional) – retry at most this many times, None means retry forever

  • delay (float) – time to wait between retries in seconds

  • delay_factor (float) – multiply delay between retries by this factor

Raises:

  • error – if at_most is exceeded the last error is re-raised

  • Exception – any exception raised by func that does not match error

Returns:

whatever is returned by func

Return type:

object