dataexamples tidy

[casperdcl]

Changes

OOP tidy of #1712

• rebase after Dataexample update #1774
• drop unused imports
• added abc.ABC -> BaseTestData -> TestData,NexusTestData,RemoteTestData
• dropped some **kwargs (Use of **kwargs in methods and functions signature is confusing #1115)
• drop _download_and_extract_from_url
• use class properties more
• prefix underscore on private/protected members

Testing you performed

Related issues/links

• Download data in dataexamples #1712
• Use of **kwargs in methods and functions signature is confusing #1115

Checklist

• I have performed a self-review of my code
• I have added docstrings in line with the guidance in the developer guide
• I have updated the relevant documentation
• I have implemented unit tests that cover any new or modified functionality
• CHANGELOG.md has been updated with any functionality change
• Request review from all relevant developers
• Change pull request label to 'Waiting for review'

Contribution Notes

Please read and adhere to the developer guide and local patterns and conventions.

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License
• I confirm that the contribution does not violate any intellectual property rights of third parties

[casperdcl]

@hrobarts I think you're missing a @classmethod def get(...) here

[hrobarts]

It's not obvious which file you would want to get from the sandstone dataset. I was thinking of just having the download function then the user can load whichever one they need. That's how I would use it in the how-to. But maybe that's a bad idea. What do you think @paskino ?

[casperdcl]

Could add an extra argument to the get function here to select the file?

[casperdcl]

btw @hrobarts why not this instead? It will prompt if not already downloaded...

Suggested change

	try:
	loader = ZEISSDataReader(file_name=filepath)
	return loader.read()
	except FileNotFoundError as exc:
	raise ValueError(f"Specify a different data_dir or download data with `{cls.__name__}({data_dir}).download_data()`") from exc
	self.download_data()
	loader = ZEISSDataReader(file_name=filepath)
	return loader.read()

[hrobarts]

We had some discussion about wanting to keep the download separate from get so the user has to actively request the download. But I agree as we have the prompt before downloading this would be neater...

[casperdcl]

also could have def get(..., missing='prompt' / 'download' / 'error') to control (default) behaviour

[hrobarts]

I think we sometimes want to just download the data without getting it e.g. in the how-to for the readers, the purpose is to show the loading step. In that case I think we need to keep data_dir as an argument and maybe keep this as a class method??

[casperdcl]

FYI zenodo_get>=1.6.1 will be on conda-forge as soon as conda-forge/zenodo_get-feedstock#10 is merged. It's already on PyPI (pip).