Saves pypesto and python version to the problem.

[PaulJonasJost]

As the problem is generally saved alongside the result, it gives access to the version of pypesto and python that was used for optimization.

Would something like "metadata" of a result object make sense? Basically informative string representations of the engine, optimizer, problem/objective, alongside necessary versions?

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[PaulJonasJost]

I agree that it's useful! are there cases where it's not possible to save the problem to hdf5?

No there should not be any, but you could theoretically specify NOT to save it.

Is the assumption that one result file contains on results obtained from the same pypesto/python version?

Yes correct that is the assumption currently. I think long term having it in the OptimizerResult would perhaps be better with a set of other "metadata" collections. My list of things I would like to somewhat safe would be the following (happy for any additional ones)

• [ ] Optimizer: version + settings
• [ ] pypesto, python version
• [ ] objective type (and if applicable version + basic settings)
• [ ] engine type
• [ ] Date of optimization

I think for many things it might be useful to alter the __str__ representation and just hand that over?

[dilpath]

Could change class OptimizerResult(dict), class ProfileResult(dict), etc. to instead inherit from some class TaskResult(dict) that looks like

class TaskResult(dict):
    def __init__(self):
        self.set_common_metadata()

    def set_common_metadata(self):
        self.metadata = {
            "python_version": ...,
            "pypesto_version": ...,
        }

and then e.g.

class OptimizerResult(TaskResult):
    def __init__(self, ...):
        super().__init__()

    def set_task_metadata(self, optimizer: pypesto.optimize.Optimizer, engine: ...):
        self.metadata['optimizer'] = type(optimizer)
        self.metadata['engine'] = type(engine)
        ...

Then just need to make sure the TaskResult.metadata dict is saved in each result storage method, and call OptimizerResult.set_task_metadata(...) inside pypesto.optimize.minimize after creating the OptimizerResult.