Add a method to access a vizier catalog's metadata information

[ManonMarchand]

Hello astroquery,

What the PR does

This PR adds a method to astroquery.vizier.VizierClass to retrieve metadata information for a given catalog. This should solve these issues :

• Origin article Vizier catalog #1454 Access origin article

>>> from astroquery.vizier import Vizier
>>> Vizier(catalog="VII/74A").get_catalog_metadata()["origin_article"]
<MaskedColumn name='origin_article' dtype='object' description='A bibliographic reference from which the present resource is derived or extracted.' length=1>
1966ApJS...14....1A

• Add method to access Vizier metadata #1467 Access all metadata

>>> from astroquery.vizier import Vizier
>>> Vizier(catalog="VII/74A").get_catalog_metadata()
<Table length=1>
          title            authors                                                                    description                                                                      origin_article   ...       created             updated       waveband other_identifier
          object            object                                                                       object                                                                            object       ...        object              object        object       object     
-------------------------- -------- ----------------------------------------------------------------------------------------------------------------------------------------------- ------------------- ... ------------------- ------------------- -------- ----------------
Atlas of Peculiar Galaxies Arp H.C. This electronic version of Arp's 1966 "Atlas of Peculiar Galaxies" contains only its Table 2 published in the Astrophysical Journal Supplement. 1966ApJS...14....1A ... 1999-01-18T06:16:30 2021-10-21T00:00:00  optical                 

• Vizier catalog description #1831 Access description

>>> from astroquery.vizier import Vizier
>>> Vizier(catalog="VII/74A").get_catalog_metadata()["description"]
<MaskedColumn name='description' dtype='object' description='An account of the nature of the resource.' length=1>
This electronic version of Arp's 1966 "Atlas of Peculiar Galaxies" contains only its Table 2 published in the Astrophysical Journal Supplement.

How it's done

It's a TAP query sent to the ivoa registry with pyvo. The output is an astropy table.

Edit: This is in a draft state cause @gilleslandais will do a first review

[gilleslandais]

Thank you for the update !

I propose minor changes in sematic (to be more close from VizieR) :

description -> abstract
other_identifier -> doi

Update sql:

SELECT TOP 1 res_title as title,
               creator_seq as authors,
                res_description as abstract,
                source_value as origin_article,
                reference_url as webpage,
                created, updated,
                waveband,
                alt_identifier as doi
                FROM rr.resource NATURAL LEFT OUTER JOIN rr.capability
                NATURAL LEFT OUTER JOIN rr.interface
                NATURAL LEFT OUTER JOIN rr.alt_identifier
                WHERE ivoid = 'ivo://cds.vizier/{catalog.lower()}'"""

and add a test on alt_identifier to select only alternate identifier prefixed with "doi:" (cf VOResource 1.2, 2.2.5 Alternate Identifiers)

metadata = registry.regtap.RegistryQuery(registry.regtap.REGISTRY_BASEURL, query)
if get_query_payload:
     return metadata
# remove alternate identifier which is not a DOI
if t["doi"][0].find("doi:") < 0: 
     t["doi"][0] = ""

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (8c15f2f) 66.52% compared to head (0a342d3) 66.53%.
Report is 7 commits behind head on main.

Files	Patch %	Lines
astroquery/vizier/core.py	78.57%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2878      +/-   ##
==========================================
+ Coverage   66.52%   66.53%   +0.01%     
==========================================
  Files         235      235              
  Lines       18101    18114      +13     
==========================================
+ Hits        12041    12052      +11     
- Misses       6060     6062       +2     

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[ManonMarchand]

Gilles remarks are now implemented.

This made me realize that the doctests were skipped for vizier.core so I included them back with the tiny fixes needed to make them pass. I skipped the output in the example on Kang W51 because it's always changing.

I think it's ready for review

[bsipocz]

Looks all good, pending a very minor docstring formatting issue. I'll go ahead and commit that directly and go ahead with the merge.

Also, I noticed that there is a new failure with the remote tests which is apparently unrelated and is due to changes in astropy, so will open a PR with the fix.

[bsipocz]

Thank you @ManonMarchand!