[ARROW-8213] [Python][Dataset] Opening a dataset with a local incorrect path gives confusing error message

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.17.0
• Component/s: C++, Python
• Labels: dataset pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/24410
• Assignee: Krisztian Szucs
• Reporter: Joris Van den Bossche
• Created: 25/Mar/20 15:33
• Updated: 11/Jan/23 07:58
• Resolved: 08/Apr/20 00:48

Description

Even after the previous PRs related to local paths (https://github.com/apache/arrow/pull/6643, https://github.com/apache/arrow/pull/6655), I don't think the user experience optimal in case you are working with local files, and pass a wrong, non-existent path (eg due to a typo).

Currently, you get this error:

>>> dataset = ds.dataset("data_with_typo.parquet", format="parquet")
...
ArrowInvalid: URI has empty scheme: 'data_with_typo.parquet'

where "URI has empty scheme" is rather confusing for the user in case of a non-existent path. I think ideally we should raise a "No such file or directory" error.

I am not fully sure what the best solution is, as FileSystem.from_uri can also give other errors that we do want to propagate to the user.
The most straightforward that I am now thinking of is checking if "URI has empty scheme" is in the error message, and then rewording it, but that's not very clean ..

Issue Links

• links to: GitHub Pull Request #6854