CadcClass

class astroquery.cadc.CadcClass(url=None, tap_plus_handler=None, verbose=None, auth_session=None)

Bases: astroquery.query.BaseQuery

Class for accessing CADC data. Typical usage:

result = Cadc.query_region(‘08h45m07.5s +54d18m00s’, collection=’CFHT’)

… do something with result (optional) such as filter as in example below

urls = Cadc.get_data_urls(result[result[‘target_name’]==’Nr3491_1’])

… access data

Other ways to query the CADC data storage:

• target name:

  Cadc.query_region(SkyCoord.from_name(‘M31’))

• target name in the metadata:

  Cadc.query_name(‘M31-A-6’) # queries as a like ‘%lower(name)%’

• TAP query on the CADC metadata (CAOM2 format -

  http://www.opencadc.org/caom2/) Cadc.get_tables() # list the tables Cadc.get_table(table_name) # list table schema Cadc.query

Initialize Cadc object

Parameters

urlstr, optional, default ‘None;

a url to use instead of the default

tap_plus_handlerdeprecated

verbosedeprecated

auth_session: `requests.Session` or `pyvo.auth.authsession.AuthSession`

A existing authenticated session containing the appropriate credentials to be used by the client to communicate with the server. This is an alternative to using login/logout methods that allows clients to reuse existing session with multiple services.

Returns

——-

Cadc object

Attributes Summary

CADCDATALINK_SERVICE_URI
CADCLOGIN_SERVICE_URI
CADCTAP_SERVICE_URI
CADC_REGISTRY_URL
TIMEOUT
cadctap
data_link_url

Methods Summary

create(*args, **kwargs)	Queries the service and returns a table object.
create_async(query[, maxrec, uploads])	Creates a TAP job to execute and returns it to the caller.
exec_sync(query[, maxrec, uploads, output_file])	Run a query and return the results or save them in an output_file
get_collections()	Query CADC for all the hosted collections
get_data_urls(query_result[, ...])	Function to map the results of a CADC query into URLs to corresponding data that can be later downloaded.
get_image_list(query_result, coordinates, radius)	Function to map the results of a CADC query into URLs to corresponding data and cutouts that can be later downloaded.
get_images(coordinates, radius[, ...])	A coordinate-based query function that returns a list of fits files with cutouts around the passed in coordinates.
get_images_async(coordinates, radius[, ...])	A coordinate-based query function that returns a list of context managers with cutouts around the passed in coordinates.
get_table(table[, verbose])	Gets the specified table
get_tables([only_names, verbose])	Gets all public tables
list_async_jobs([phases, after, last, ...])	Returns all the asynchronous jobs
list_jobs(*args, **kwargs)	Queries the service and returns a table object.
load_async_job(jobid[, verbose])	Loads an asynchronous job
load_job(*args, **kwargs)	Queries the service and returns a table object.
login([user, password, certificate_file])	login allows user to authenticate to the service.
logout([verbose])	Logout.
query_name(*args, **kwargs)	Queries the service and returns a table object.
query_name_async(name)	Query CADC metadata for a name and return the corresponding metadata in
query_region(*args, **kwargs)	Queries the service and returns a table object.
query_region_async(coordinates[, radius, ...])	Queries the CADC for a region around the specified coordinates.
run_query(query, operation[, output_file, ...])	Deprecated since version 0.4.0.

Attributes Documentation

CADCDATALINK_SERVICE_URI = 'ivo://cadc.nrc.ca/caom2ops'

CADCLOGIN_SERVICE_URI = 'ivo://cadc.nrc.ca/gms'

CADCTAP_SERVICE_URI = 'ivo://cadc.nrc.ca/argus'

CADC_REGISTRY_URL = 'http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/reg/resource-caps'

TIMEOUT = 30

cadctap

data_link_url

Methods Documentation

create(*args, **kwargs)

Queries the service and returns a table object.

Creates a TAP job to execute and returns it to the caller. The caller then can start the execution and monitor the job. Typical (no error handling) sequence of events:

job = create_async(query) job = job.run().wait() job.raise_if_error() result = job.fetch_result() job.delete() # optional

See pyvo.dal.tap for details about the AsyncTAPJob

Parameters

querystr, mandatory

SQL to execute

maxrecint

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns

tableA Table object.

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

create_async(query, maxrec=None, uploads=None)

Creates a TAP job to execute and returns it to the caller. The caller then can start the execution and monitor the job. Typical (no error handling) sequence of events:

job = create_async(query) job = job.run().wait() job.raise_if_error() result = job.fetch_result() job.delete() # optional

See pyvo.dal.tap for details about the AsyncTAPJob

Parameters

querystr, mandatory

SQL to execute

maxrecint

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns

AsyncTAPJob

the query instance

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

exec_sync(query, maxrec=None, uploads=None, output_file=None)

Run a query and return the results or save them in an output_file

Parameters

querystr, mandatory

SQL to execute

maxrecint

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns

Results of running the query in (for now) votable format

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

get_collections()

Query CADC for all the hosted collections

Returns

A dictionary of collections hosted at the CADC where the key is the

collection and value represents details of that collection.

get_data_urls(query_result, include_auxiliaries=False)

Function to map the results of a CADC query into URLs to corresponding data that can be later downloaded.

The function uses the IVOA DataLink Service (http://www.ivoa.net/documents/DataLink/) implemented at the CADC. It works directly with the results produced by query_region and query_name but in principle it can work with other query results produced with the Cadc query as long as the results contain the ‘publisherID’ column. This column is part of the ‘caom2.Plane’ table.

Parameters

query_resultA Table object

Result returned by query_region or query_name. In general, the result of any CADC TAP query that contains the ‘publisherID’ column can be use here.

include_auxiliariesboolean

True to return URLs to auxiliary files such as previews, False otherwise

Returns

A list of URLs to data.

get_image_list(query_result, coordinates, radius)

Function to map the results of a CADC query into URLs to corresponding data and cutouts that can be later downloaded.

The function uses the IVOA DataLink Service (http://www.ivoa.net/documents/DataLink/) implemented at the CADC. It works directly with the results produced by query_region and query_name but in principle it can work with other query results produced with the Cadc query as long as the results contain the ‘publisherID’ column. This column is part of the ‘caom2.Plane’ table.

Parameters

query_resultA Table object

Result returned by query_region or query_name. In general, the result of any CADC TAP query that contains the ‘publisherID’ column can be used here.

coordinatesstr or astropy.coordinates.

Center of the cutout area.

radiusstr or astropy.units.Quantity.

The radius of the cutout area.

Returns

listA list of URLs to cutout data.

get_images(coordinates, radius, collection=None, get_url_list=False, show_progress=False)

A coordinate-based query function that returns a list of fits files with cutouts around the passed in coordinates.

Parameters

coordinatesstr or astropy.coordinates.

Coordinates around which to query.

radiusstr or astropy.units.Quantity

The radius of the cone search AND cutout area.

collectionstr, optional

Name of the CADC collection to query.

get_url_listbool, optional

If True, returns the list of data urls rather than the downloaded FITS files. Default is False.

show_progressbool, optional

Whether to display a progress bar if the file is downloaded from a remote server. Default is False.

Returns

listA list of HDUList objects (or a list of

str if returning urls).

get_images_async(coordinates, radius, collection=None, get_url_list=False, show_progress=False)

A coordinate-based query function that returns a list of context managers with cutouts around the passed in coordinates.

Parameters

coordinatesstr or astropy.coordinates.

Coordinates around which to query.

radiusstr or astropy.units.Quantity

The radius of the cone search AND cutout area.

collectionstr, optional

Name of the CADC collection to query.

get_url_listbool, optional

If True, returns the list of data urls rather than the list of context managers. Default is False.

show_progressbool, optional

Whether to display a progress bar if the file is downloaded from a remote server. Default is False.

Returns

listA list of context-managers that yield readable file-like objects

get_table(table, verbose=None)

Gets the specified table

Parameters

tablestr, mandatory

full qualified table name (i.e. schema name + table name)

verbosedeprecated

Returns

A table object

get_tables(only_names=False, verbose=None)

Gets all public tables

Parameters

only_namesbool, optional, default False

True to load table names only

verbosedeprecated

Returns

A list of table objects

list_async_jobs(phases=None, after=None, last=None, short_description=True, verbose=None)

Returns all the asynchronous jobs

Parameters

phases: list of str

Union of job phases to filter the results by.

after: datetime

Return only jobs created after this datetime

last: int

Return only the most recent number of jobs

short_description: flag - True or False

If True, the jobs in the list will contain only the information corresponding to the TAP ShortJobDescription object (job ID, phase, run ID, owner ID and creation ID) whereas if False, a separate GET call to each job is performed for the complete job description

verbosedeprecated

Returns

A list of Job objects

list_jobs(*args, **kwargs)

Queries the service and returns a table object.

Returns all the asynchronous jobs

Parameters

phases: list of str

Union of job phases to filter the results by.

after: datetime

Return only jobs created after this datetime

last: int

Return only the most recent number of jobs

short_description: flag - True or False

If True, the jobs in the list will contain only the information corresponding to the TAP ShortJobDescription object (job ID, phase, run ID, owner ID and creation ID) whereas if False, a separate GET call to each job is performed for the complete job description

verbosedeprecated

Returns

tableA Table object.

load_async_job(jobid, verbose=None)

Loads an asynchronous job

Parameters

jobidstr, mandatory

job identifier

verbosedeprecated

Returns

A Job object

load_job(*args, **kwargs)

Queries the service and returns a table object.

Loads an asynchronous job

Parameters

jobidstr, mandatory

job identifier

verbosedeprecated

Returns

tableA Table object.

login(user=None, password=None, certificate_file=None)

login allows user to authenticate to the service. Both user/password and https client certificates are supported.

Alternatively, the Cadc class can be instantiated with an authenticated session.

Parameters

userstr, required if certificate is None

username to login with

passwordstr, required if user is set

password to login with

certificatestr, required if user is None

path to certificate to use with logging in

logout(verbose=None)

Logout. Anonymous access with all the subsequent use of the object. Note that the original session is not affected (in case it was passed when the object was first instantiated)

Parameters

verbosedeprecated

query_name(*args, **kwargs)

Queries the service and returns a table object.

Query CADC metadata for a name and return the corresponding metadata in

the CAOM2 format (http://www.opencadc.org/caom2/).

Parameters

name: str

name of object to query for

Returns

tableA Table object.

query_name_async(name)

Query CADC metadata for a name and return the corresponding metadata in

the CAOM2 format (http://www.opencadc.org/caom2/).

Parameters

name: str

name of object to query for

Returns

responseTable

Results of the query in a tabular format.

query_region(*args, **kwargs)

Queries the service and returns a table object.

Queries the CADC for a region around the specified coordinates.

Parameters

coordinatesstr or astropy.coordinates.

coordinates around which to query

radiusstr or astropy.units.Quantity.

the radius of the cone search

collection: Name of the CADC collection to query, optional

get_query_payloadbool, optional

Just return the dict of HTTP request parameters.

Returns

tableA Table object.

query_region_async(coordinates, radius=<Quantity 0.01666667 deg>, collection=None, get_query_payload=False)

Queries the CADC for a region around the specified coordinates.

Parameters

coordinatesstr or astropy.coordinates.

coordinates around which to query

radiusstr or astropy.units.Quantity.

the radius of the cone search

collection: Name of the CADC collection to query, optional

get_query_payloadbool, optional

Just return the dict of HTTP request parameters.

Returns

responserequests.Response

The HTTP response returned from the service. All async methods should return the raw HTTP response.

run_query(query, operation, output_file=None, output_format='votable', verbose=None, background=False, upload_resource=None, upload_table_name=None)

Deprecated since version 0.4.0: Use exec_sync or create_async instead

Runs a query

Parameters

querystr, mandatory

query to be executed

operationstr, mandatory,

‘sync’ or ‘async’ to run a synchronous or asynchronous job

output_filestr, optional, default None

file name where the results are saved if dumpToFile is True. If this parameter is not provided, the jobid is used instead

output_formatstr, optional, default ‘votable’

results format, ‘csv’, ‘tsv’ and ‘votable’

verbosedeprecated

save_to_filebool, optional, default ‘False’

if True, the results are saved in a file instead of using memory

backgroundbool, optional, default ‘False’

when the job is executed in asynchronous mode, this flag specifies whether the execution will wait until results are available

upload_resource: str, optional, default None

resource to be uploaded to UPLOAD_SCHEMA

upload_table_name: str, required if uploadResource is provided,

default None resource temporary table name associated to the uploaded resource

Returns

A Job object