DALQuery

class pyvo.dal.query.DALQuery(baseurl, protocol=None, version=None)[source]

Bases: dict

a class for preparing a query to a particular service. Query constraints are added via its service type-specific methods. The various execute() functions will submit the query and return the results.

The base URL for the query can be changed via the baseurl property.

initialize the query object with a baseurl

Attributes Summary

baseurl the base URL that this query will be sent to when one of the
protocol The service protocol supported by this query object (read-only).
std_parameters
version The version of the service protocol supported by this query object (read-only).

Methods Summary

execute() submit the query and return the results as a Results subclass instance
execute_raw() submit the query and return the raw VOTable XML as a string.
execute_stream() submit the query and return the raw VOTable XML as a file stream
execute_votable() submit the query and return the results as an AstroPy votable instance
getqueryurl() return the GET URL that encodes the current query. This is the
submit() does the actual request

Attributes Documentation

baseurl

the base URL that this query will be sent to when one of the execute functions is called.

protocol

The service protocol supported by this query object (read-only).

std_parameters = []
version

The version of the service protocol supported by this query object (read-only).

Methods Documentation

execute()[source]

submit the query and return the results as a Results subclass instance

Raises:

DALServiceError

for errors connecting to or communicating with the service

DALQueryError

for errors either in the input query syntax or other user errors detected by the service

DALFormatError

for errors parsing the VOTable response

execute_raw()[source]

submit the query and return the raw VOTable XML as a string.

Raises:

DALServiceError

for errors connecting to or communicating with the service

DALQueryError

for errors in the input query syntax

execute_stream()[source]

submit the query and return the raw VOTable XML as a file stream

Raises:

DALServiceError

for errors connecting to or communicating with the service

DALQueryError

for errors in the input query syntax

execute_votable()[source]

submit the query and return the results as an AstroPy votable instance

Returns:

astropy.io.votable.tree.Table

an Astropy votable Table instance

Raises:

DALServiceError

for errors connecting to or communicating with the service

DALFormatError

for errors parsing the VOTable response

DALQueryError

for errors in the input query syntax

See also

astropy.io.votable, DALServiceError, DALFormatError, DALQueryError

getqueryurl()[source]

return the GET URL that encodes the current query. This is the URL that the execute functions will use if called next.

Parameters:

lax : bool

if False (default), a DALQueryError exception will be raised if the current set of parameters cannot be used to form a legal query. This implementation does no syntax checking; thus, this argument is ignored.

Returns:

str

the encoded query URL

Raises:

DALQueryError

when lax=False, for errors in the input query syntax

See also

DALQueryError

submit()[source]

does the actual request