VOSDatabase

class astropy.vo.client.vos_catalog.VOSDatabase(tree)

Bases: astropy.vo.client.vos_catalog.VOSBase

A class to represent a collection of VOSCatalog.

Parameters:

tree : JSON tree

Raises:

VOSError

If given tree does not have ‘catalogs’ key or catalog is invalid.

Attributes Summary

version

Database version number.

Methods Summary

add_catalog(name, cat[, allow_duplicate_url])	Add a catalog to database.
add_catalog_by_url(name, url, **kwargs)	Like add_catalog() but the catalog is created with only the given name and access URL.
create_empty()	Create an empty database of VO services.
delete_catalog(name)	Delete a catalog from database with given name.
delete_catalog_by_url(url)	Like delete_catalog() but using access URL.
from_json(filename, **kwargs)	Create a database of VO services from a JSON file.
from_registry(registry_url[, timeout])	Create a database of VO services from VO registry URL.
get_catalog(name)	Get one catalog of given name.
get_catalog_by_url(url)	Like get_catalog() but using access URL look-up.
get_catalogs()	Iterator to get all catalogs.
get_catalogs_by_url(url)	Like get_catalogs() but using access URL look-up.
list_catalogs([pattern, sort])	List catalog names.
list_catalogs_by_url([pattern, sort])	Like list_catalogs() but using access URL.
merge(other, **kwargs)	Merge two database together.
to_json(filename[, clobber])	Write database content to a JSON file.

Attributes Documentation

version

Database version number.

Methods Documentation

add_catalog(name, cat, allow_duplicate_url=False)

Add a catalog to database.

Parameters:

name : str

Primary key for the catalog.

cat : VOSCatalog

Catalog to add.

allow_duplicate_url : bool

Allow catalog with duplicate access URL?

Raises:

VOSError

Invalid catalog.

DuplicateCatalogName

Catalog with given name already exists.

DuplicateCatalogURL

Catalog with given access URL already exists.

add_catalog_by_url(name, url, **kwargs)

Like add_catalog() but the catalog is created with only the given name and access URL.

Parameters:

name : str

Primary key for the catalog.

url : str

Access URL of the service. This is used to build queries.

kwargs : dict

Keywords accepted by add_catalog().

classmethod create_empty()

Create an empty database of VO services.

Empty database format:

{
    "__version__": 1,
    "catalogs" : {
    }
}

Returns:

db : VOSDatabase

Empty database.

delete_catalog(name)

Delete a catalog from database with given name.

Parameters:

name : str

Primary key identifying the catalog.

Raises:

MissingCatalog

If catalog is not found.

delete_catalog_by_url(url)

Like delete_catalog() but using access URL. On multiple matches, all matches are deleted.

classmethod from_json(filename, **kwargs)

Create a database of VO services from a JSON file.

Example JSON format for Cone Search:

{
    "__version__": 1,
    "catalogs" : {
        "My Cone Search": {
            "capabilityClass": "ConeSearch",
            "title": "My Cone Search",
            "url": "http://foo/cgi-bin/search?CAT=bar&",
            ...
        },
        "Another Cone Search": {
            ...
        }
    }
}

Parameters:

filename : str

JSON file.

kwargs : dict

Keywords accepted by get_readable_fileobj().

Returns:

db : VOSDatabase

Database from given file.

classmethod from_registry(registry_url, timeout=60, **kwargs)

Create a database of VO services from VO registry URL.

This is described in detail in Building the Database from Registry, except for the validate_xxx keys that are added by the validator itself.

Parameters:

registry_url : str

URL of VO registry that returns a VO Table. For example, see astropy.vo.validator.validate.CS_MSTR_LIST. Pedantic is automatically set to False for parsing.

timeout : number

Temporarily set astropy.utils.data.REMOTE_TIMEOUT to this value to avoid time out error while reading the entire registry.

kwargs : dict

Keywords accepted by get_readable_fileobj().

Returns:

db : VOSDatabase

Database from given registry.

Raises:

VOSError

Invalid VO registry.

get_catalog(name)

Get one catalog of given name.

Parameters:

name : str

Primary key identifying the catalog.

Returns:

obj : VOSCatalog

Raises:

MissingCatalog

If catalog is not found.

get_catalog_by_url(url)

Like get_catalog() but using access URL look-up. On multiple matches, only first match is returned.

get_catalogs()

Iterator to get all catalogs.

get_catalogs_by_url(url)

Like get_catalogs() but using access URL look-up.

list_catalogs(pattern=None, sort=True)

List catalog names.

Parameters:

pattern : str or None

If given string is anywhere in a catalog name, it is considered a matching catalog. It accepts patterns as in fnmatch and is case-insensitive. By default, all catalogs are returned.

sort : bool

Sort output in alphabetical order. If not sorted, the order depends on dictionary hashing. Default is True.

Returns:

out_arr : list of str

List of catalog names.

list_catalogs_by_url(pattern=None, sort=True)

Like list_catalogs() but using access URL.

merge(other, **kwargs)

Merge two database together.

Parameters:

other : VOSDatabase

The other database to merge.

kwargs : dict

Keywords accepted by add_catalog().

Returns:

db : VOSDatabase

Merged database.

Raises:

VOSError

Invalid database or incompatible version.

to_json(filename, clobber=False)

Write database content to a JSON file.

Parameters:

filename : str

JSON file.

clobber : bool

Overwrite existing file?

Raises:

OSError

File exists.