pymods 2.0.3

Utility class wrapping lxml for reading data from MODS v3.4 XML metadata into Python data types.

pymods is utility module for working with the Library of Congress’s MODS XML standard: Metadata Description Schema (MODS). It is a utility wrapper for the lxml module specific to deserializing data out of MODSXML into python data types.

If you need a module to serialize data into MODSXML, see the other pymods by Matt Cordial.

Installing

Recommended:

pip install pymods

Using

Basics

XML is parsed using the MODSReader class:

mods_records = pymods.MODSReader('some_file.xml')

Individual records are stored as an iterator of the MODSRecord object:

In [5]: for record in mods_records:
  ....:    print(record)
  ....:
<Element {http://www.loc.gov/mods/v3}mods at 0x47a69f8>
<Element {http://www.loc.gov/mods/v3}mods at 0x47fd908>
<Element {http://www.loc.gov/mods/v3}mods at 0x47fda48>

MODSReader will work with mods:modsCollection documents, outputs from OAI-PMH feeds, or individual MODSXML documents with mods:mods as the root element.

pymods.MODSRecord

The MODSReader class parses each mods:mods element into a pymods.MODSRecord object. pymods.MODSRecord is a custom wrapper class for the lxml.ElementBase class. All children of pymods.Record inherit the lxml._Element and lxml.ElementBase methods.

In [6]: record = next(pymods.MODSReader('example.xml'))
In [7]: print(record.nsmap)
{'dcterms': 'http://purl.org/dc/terms/', 'xsi': 'http://www.w3.org/2001/XMLSchema-instance', None: 'http://www.loc.gov/mods/v3', 'flvc': 'info:flvc/manifest/v1', 'xlink': 'http://www.w3.org/1999/xlink', 'mods': 'http://www.loc.gov/mods/v3'}

In [8]: for child in record.iterdescendants():
  ....:    print(child.tag)

{http://www.loc.gov/mods/v3}identifier
{http://www.loc.gov/mods/v3}extension
{info:flvc/manifest/v1}flvc
{info:flvc/manifest/v1}owningInstitution
{info:flvc/manifest/v1}submittingInstitution
{http://www.loc.gov/mods/v3}titleInfo
{http://www.loc.gov/mods/v3}title
{http://www.loc.gov/mods/v3}name
{http://www.loc.gov/mods/v3}namePart
{http://www.loc.gov/mods/v3}role
{http://www.loc.gov/mods/v3}roleTerm
{http://www.loc.gov/mods/v3}roleTerm
{http://www.loc.gov/mods/v3}typeOfResource
{http://www.loc.gov/mods/v3}genre
...

Methods

All functions return data either as a string, list, list of named tuples. See the appropriate docstring for details.

>>> record.genre?
Type:        property
String form: <property object at 0x0000000004812C78>
Docstring:
Accesses mods:genre element.
:return: A list containing Genre elements with term, authority,
    authorityURI, and valueURI attributes.

Examples

Importing

from pymods import MODSReader, MODSRecord

Parsing a file

In [10]: mods = MODSReader('example.xml')
In [11]: for record in mods:
   ....:    print(record.dates)
   ....:
[Date(text='1966-12-08', type='{http://www.loc.gov/mods/v3}dateCreated')]
None
[Date(text='1987-02', type='{http://www.loc.gov/mods/v3}dateIssued')]

Simple tasks

Generating a title list

In [14]: for record in mods:
   ....:     print(record.titles)
   ....:
['Fire Line System']
['$93,668.90. One Mill Tax Apportioned by Various Ways Proposed']
['Broward NOW News: National Organization for Women, February 1987']

Creating a subject list

In [17]: for record in mods:
   ....:     for subject in record.subjects:
   ....:         print(subject.text)
   ....:
Concert halls
Architecture
Architectural drawings
Structural systems
Structural systems drawings
Structural drawings
Safety equipment
Construction
Mechanics
Structural optimization
Architectural design
Fire prevention--Safety measures
Taxes
Tax payers
Tax collection
Organizations
Feminism
Sex discrimination against women
Women's rights
Equal rights amendments
Women--Societies and clubs
National Organization for Women

More complex tasks

Creating a list of subject URI’s only for LCSH subjects

In [18]: for record in mods:
   ....:     for subject in record.subjects:
   ....:         if 'lcsh' == subject.authority:
   ....:             print(subject.uri)
   ....:
http://id.loc.gov/authorities/subjects/sh85082767
http://id.loc.gov/authorities/subjects/sh88004614
http://id.loc.gov/authorities/subjects/sh85132810
http://id.loc.gov/authorities/subjects/sh85147343

Get URLs for objects using a No Copyright US rightsstatement.org URI

In [23]: for record in mods:
   ....:     for rights_elem in record.rights
   ....:         if rights_elem.uri == 'http://rightsstatements.org/vocab/NoC-US/1.0/':
   ....:             print(record.purl)
   ....:
http://purl.flvc.org/fsu/fd/FSU_MSS0204_B01_F10_09
http://purl.flvc.org/fsu/fd/FSU_MSS2008003_B18_F01_004