rdftools 0.2.0

Description:

rdftools 0.2.0

# RDF ToolsThis package consists of a set of command-line tools that do interesting things with RDF and SPARQL.The functionality is provided by RDFLib, and while that provides a set of commands those provided here are somewhat more extensive and also based upon a common command framework that can be extended easily for more cases.[](https://travis-ci.org/johnstonskj/rdftools)[](https://coveralls.io/github/johnstonskj/rdftools?branch=master)[](https://codeclimate.com/github/johnstonskj/rdftools/maintainability)[](https://requires.io/github/johnstonskj/rdftools/requirements/?branch=master)<!--[](https://readthedocs.org/projects/rdftools)-->[](https://github.com/johnstonskj/rdftools/stargazers)[](https://pypi.python.org/pypi/rdftools)[](https://pypi.python.org/pypi/rdftools)[](https://pypi.python.org/pypi/tdftools)## UsageThe tooling uses a common starting command, `rdf`, that then executes sub-commands. As expected, the command has a help function and lists the supported sub-commands as _positional arguments_. These sub-commands also have their own help.```rdf−husage:rdf[−h][−v]validate,convert,select,query...RDFtoolpositionalarguments:validate,convert,select,shell,querysubargsoptionalarguments:−h,−−helpshowthishelpmessageandexit−v,−−verbose‘‘‘Thecurrentlysupportedsub−commandsareasfollows.∗‘convert‘−convertfilesbetweendifferentRDFrepresentations(NTriples,Notation3,XML,...).∗‘query‘−executeSPARQLqueriesoverRDFfiles.∗‘select‘−simpleprojectionsfromRDFfiles.∗‘shell‘−runaninteractiveshellsession.∗‘validate‘−validateanRDFfile.Anexample,runningaSPARQLqueryoveradownloadedfileisshownbelow.‘‘‘ rdf query -i ~/social.n3 -r n3 -q "SELECT DISTINCT ?person ?topic WHERE { ?person <http://example.org/social/relationship/1.0/likes> ?topic. }"person topic============================================== =============================================http://amazon.com/cprm/customers/1.0/Alice http://amazon.com/cprm/entities/1.0/Divinghttp://amazon.com/cprm/customers/1.0/Bob http://amazon.com/cprm/entities/1.0/Divinghttp://amazon.com/cprm/customers/1.0/Alice http://amazon.com/cprm/entities/1.0/Shoes3 rows returned in 1.629622 seconds.```## DebuggingThe `-v` parameter to either `rdf` or one of the sub-commands controls the standard Python logging level. It can be stated multiple times to increase the logging; `-v` for warnings, `-vv` for informational, `-vvv` for debug.## Interactive ShellFor a more interactive exploration of RDF data you can run `rdf shell` which gives you access to a lot of the same functions in the separate tools. The shell has a single common graph into which you can load data from external files (and stores in the future), and run SPARQL queries. The shell also has a default initialization file, so commonly used prefixes, common data, etc. can be loaded before you start your session.```$ rdf shellRDF Shell, v0.1.0.reading commands from file /Users/simonjo/.rdfshrcGraph updated with 40 statements.>```As you might expect, the shell supports a `help` function and command completion as well as a persistent history.### Initialization FileThe default location for this is `~/.rdfshrc`, all commands are read as if you typed them into the shell.### History FileThe default location for this is `~/.rdfsh_hist`, it will be read at startup and updated on closing the shell.## ExtendingNew commands are added as modules in the `rdftools/scripts` folder and have the following structure.```pythonimport rdftoolsdef main(): (LOG, cmd) = rdftools.startup('Tool description.', add_args=None) ...```The `add_args` parameter is used to add additional command-line arguments to the common `argparse` structure. The function, if required, takes in a parser object and returns it. The common command line arguments include verbosity, help, and reading files.```pythondef add_args(parser): return parser```The results from `startup` are a standard logger and an (`ArgumentParser`) `Namespace` object. The tool can then use the functions `read`, `read_into`, `read_all`, `write`, and `query` to perform common operations on RDF files.Extending the shell is also pretty simple, you add a function of the following form, it always takes a context object first, and the doc string will be used by default as the displayed help for your command. Arguments may be parsed for more structure, and `print()` is used extensively for user feedback. Note that you must always return the context, whether you updated it or not. The `add_command` function will install it into the shell, enabling help and command completion.```pythondef echo(context, args): """ echo text Echo back the following text.""" print(args) return contextadd_command(echo)```## References* [RDF Working Group](https://www.w3.org/2011/rdf-wg/wiki/Main_Page)* [SPARQL Overview](https://www.w3.org/TR/sparql11-overview/)* [RDFLib](https://github.com/RDFLib/rdflib)* [Travis Project](https://travis-ci.org/johnstonskj/rdftools)* [Coveralls Project](https://coveralls.io/github/johnstonskj/rdftools)