csvwlib 0.1.1

Python implementation of CSV on the Web

About

csvw-py is a python implementation of W3C CSV on the Web recommendations. It enables merging CSV file and associated metadata into JSON or RDF.

Installation

pip install csvw-py

Usage

The library exposes one class - CSVWConverter which has methods to_json() and to_rdf() Both these methods have similar API. They receive 3+ parameters:

• csv_url - URL of CSV file, default None

• metadata_url - the URL of metadata file, default None

• mode - conversion mode, default standard, second possible value is minimal

The are 3 ways of starting conversion process.

• pass only csv_url - corresponding metadata will be looked up based on csv_url as described in Locating Metadata

• pass both csv_url and metadata_url - metadata by user will be used. If url field is set in metadata, the CSV file will be retrieved from that location which can cause, that passed csv_url will be ignored

• pass only metadata_url - associated CSV files will be retrieved based on metadata url field

You can also specify the conversion mode - standard or minimal, the default is standard. From documentation

Standard mode conversion frames the information gleaned from the cells of the tabular data with details of the rows, tables, and a group of tables within which that information is provided.

Minimal mode conversion includes only the information gleaned from the cells of the tabular data.

After conversion to JSON, you receive a dict object, when converting to RDF it is more complex. If you pass format parameter, graph will be serialized to this format and returned as string. From rdflib docs

Format support can be extended with plugins, but ‘xml’, ‘n3’, ‘turtle’, ‘nt’, ‘pretty-xml’, ‘trix’, ‘trig’ and ‘nquads’ are built in.

If you don’t specify the format, you will receive a rdflib.Graph object.

Examples

Example files can be found at http://w3c.github.io/csvw/tests/

Common import for all examples:

from csvw-py import CSVWConverter

Start with csv

CSVWConverter.to_rdf('http://w3c.github.io/csvw/tests/test001.csv', format='ttl')

Minimal mode

CSVWConverter.to_rdf('http://w3c.github.io/csvw/tests/tree-ops.csv', mode='minimal', format='ttl')

Start with metadata

CSVWConverter.to_rdf(metadata_url='http://w3c.github.io/csvw/tests/test188-metadata.json', format='ttl')

Both CSV and metadata URL specified

CSVWConverter.to_rdf('http://w3c.github.io/csvw/tests/tree-ops.csv', 'http://w3c.github.io/csvw/tests/tree-ops.csv', format='ttl')

Start with metadata

CSVWConverter.to_json('http://w3c.github.io/csvw/tests/countries.json')

Start with csv

CSVWConverter.to_json('http://w3c.github.io/csvw/tests/test001.csv')