Topi

Topi ("TIND Object Python Interface") is a Python package for getting basic data from a TIND server.

TIND is an integrated library system. The Caltech Library uses a hosted solution by TIND for its library catalog.  Recent versions of TIND provide a REST API for getting a subset of information using network calls.  To make writing interfaces and automation scripts in Python easier, the Caltech Library Digital Library Development team developed Topi ("TIND Object Python Interface"), a Python package that provides an object-oriented interface to data in a TIND catalog.

Topi is not a complete API for interacting with TIND instances.  At this time, it provides an interface for retrieving only  two kinds of objects: bibliographic records, and items/holdings associated with those records.

A "topi" is also a species of antelope found in Africa.  The topi is currently classified as vulnerable by the International Union for Conservation of Nature (IUCN) due to threats that include human development, hunting and droughts.

Installation

The instructions below assume you have a Python interpreter installed on your computer; if that's not the case, please first install Python version 3 and familiarize yourself with running Python programs on your system.

On Linux, macOS, and Windows operating systems, you should be able to install topi with pip.  To install topi from the Python package repository (PyPI), run the following command:

python3 -m pip install topi

As an alternative to getting it from PyPI, you can use pip to install topi directly from GitHub, like this:

python3 -m pip install git+https://github.com/caltechlibrary/topi.git

Usage

Topi is a application programming interface (API) library; it does not offer a command-line interface.  There are three main option classes in Topi: Tind, TindRecord, and TindItem.  The rest of this section describes these classes and how to use them.

Object classes

Tind

An object of the Tind class serves as the main point of interaction with a TIND server.  The constructor for Tind takes only one argument: the base network URL for the server.  Using it is very simple:

from topi import Tind

tind = Tind('https://caltech.tind.io')

An instance of the Tind class offers just two methods: record, to create TindRecord objects, and item, to create TindItem objects.  These object classes are described below.

TindRecord

This object class represents a bibliographic record in a TIND database.  The fields of the record are derived from the MARC representation of the bibliographic record in TIND.  The following are the fields in a record object in Topi:

A TindRecord object can be obtained using the factory method record(...) on the Tind interface object.  This method takes one of two mutually-exclusive keyword arguments: either a TIND record identifier, or a MARC XML string obtained from a TIND server for a TIND bibliographic record.  Here is an example:

from topi import Tind

tind = Tind('https://caltech.tind.io')
rec  = tind.record(tind_id = 680311)

Note the use of the keyword argument.  Below is an example of how to create a record from an existing MARC XML file obtained from a TIND server some other way – let's assume it is stored a file named downloaded-marc.xml:

from topi import Tind

with open('downloaded_marc.xml', 'r') as xf:
    xml_string = xf.read()

tind = Tind('https://caltech.tind.io')
rec  = tind.record(marc_xml = xml_string)

The thumbnail_url field is lazily evaluated: its value is only obtained from the TIND server the first time the field is accessed by a calling program.  This is more efficient for situations where the thumbnail is never needed by an application, but it does mean that there is a delay the first time the field is accessed.

TindItem

Conceptually, in TIND an "item" is a specific copy of a work; this copy has a barcode and other item-specific information such as a location.  Each item is associated with a TIND record (represented by a TindRecord in Topi, described above).  The following are the fields in an item object in Topi:

With Topi, a TindItem object can be obtained using the factory method item(...) on the Tind interface object.  This method takes a single argument: a barcode.  Here is an example:

from topi import Tind

tind = Tind('https://caltech.tind.io')
item = tind.item(35047018228114)

Item records have parent pointers to the corresponding bibliographic record, in the form of a TindRecord.  Thus, given an item object, it's possible to look up the rest of the bibliographic record simply by dereferencing the .parent field:

from topi import Tind

tind = Tind('https://caltech.tind.io')
item = tind.item(35047018228114)
print(item.parent.title)

Calling the item method on Tind will return an empty TindItem object.

Additional notes

Topi fills out the thumbnail_url field of a TindRecord object by using TIND's API for the purpose.  This only retrieves what a given TIND database contains for the cover image of a work.  Other sources such as the Open Library Covers API may have cover images that a TIND database lacks, but it is outside the scope of Topi to provide an interface for looking outside the TIND database.

Known issues and limitations

Currently, the coverage of the fields in TindRecord is limited.  Not all fields of a MARC XML record are mapped to fields in TindRecord at this time.  (Code contributions are welcome!)

GitHub

GitHub - caltechlibrary/topi: Simple Python objects for getting data from TIND

Simple Python objects for getting data from TIND. Contribute to caltechlibrary/topi development by creating an account on GitHub.

GitHubcaltechlibrary