Module datafind

source code

The client library for the LIGO Data Replicator (LDR) service.

The DataFind service allows users to query for the location of Gravitational-Wave Frame (GWF) files containing data from the current LIGO and Virgo gravitational-wave detectors.

This module defines the GWDataFindHTTPConnection and GWDataFindHTTPSConnection class objects, for connecting to an LDR server in open and authenticated access modes respectively. The authenticated GWDataFindHTTPSConnection connection requires users have a valid X509 certificate that is registered with the server in question.

A new connection can be opened as follows:

>>> from glue.datafind import GWDataFindHTTPConnection
>>> connection = GWDataFindHTTPConnection(host, port)

and similar for the HTTPS version.

Users on the LIGO Data Grid (LDG) can connect without giving the name of the relevant host, so long as the LIGO_DATAFIND_SERVER environment variable is defined:

>>> connection = GWDataFindHTTPConnection()

Queries for frames can be made using the find_frame_urls method of the relevant connection:

>>> cache = connection.find_frame_urls('L', 'L1_R', 1093564816, 1093651216)

By default, the returned Cache object includes both gsiftp and local file versions of each frame, but the urlfile keyword argument can be given to return only one of those:

>>> cache = connection.find_frame_urls('L', 'L1_R', 1093564816, 1093651216, urltype='file')

See the documentation for each connection method for more detailed examples.