issues: 891281614

This data as json

id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
891281614 MDU6SXNzdWU4OTEyODE2MTQ= 5302 Suggesting specific IO backends to install when open_dataset() fails 1217238 closed 0     3 2021-05-13T18:45:28Z 2021-06-23T08:18:07Z 2021-06-23T08:18:07Z MEMBER      

Currently, Xarray's internal backends don't get registered unless the necessary dependencies are installed: https://github.com/pydata/xarray/blob/1305d9b624723b86050ca5b2d854e5326bbaa8e6/xarray/backends/netCDF4_.py#L567-L568

In order to facilitating suggesting a specific backend to install (e.g., to improve error messages from opening tutorial datasets https://github.com/pydata/xarray/issues/5291), I would suggest that Xarray always registers its own backend entrypoints. Then we make the following changes to the plugin protocol:

  • guess_can_open() should work regardless of whether the underlying backend is installed
  • installed() returns a boolean reporting whether backend is installed. The default method in the base class would return True, for backwards compatibility.
  • open_dataset() of course should error if the backend is not installed.

This will let us leverage the existing guess_can_open() functionality to suggest specific optional dependencies to install. E.g., if you supply a netCDF3 file: Xarray cannot find a matching installed backend for this file in the installed backends ["h5netcdf"]. Consider installing one of the following backends which reports a match: ["scipy", "netcdf4"]

Does this reasonable and worthwhile?

CC @aurghs @alexamici 

{
    "url": "https://api.github.com/repos/pydata/xarray/issues/5302/reactions",
    "total_count": 4,
    "+1": 4,
    "-1": 0,
    "laugh": 0,
    "hooray": 0,
    "confused": 0,
    "heart": 0,
    "rocket": 0,
    "eyes": 0
}
   completed 13221727 issue

Links from other tables