Hi Jean,

> So, I was wondering if any one had an example Python or Perl script for
> reading RDF/XML, Turtle, or N-triples file.  A simple/partial example
> would be fine.

I worked on a Perl script for reading RDF during last year's OCLC Developer House event. 

I used the Perl "RDF::Helper" module since it claimed to "Provide a consistent, high-level API for working with RDF with Perl" [1].  There was a bit of a learning curve and I was not able to find much in the way of RDF::Helper code examples on the interwebs.

For the OCLC Developer House project, we were extracting, parsing, and displaying a library's hours from institutional data in the OCLC WorldCat Registry [2].  I've attached a perl "proof-of-concept" script and a couple of screen shots showing output.  The script file has an additional ".txt" file extension for safe travels thru email.  The script requires non-core perl module(s), as well as specifying a path to a CA Root certs file (for HTTPS gets).

The other Developer House "Registry Hours" project team members worked on a PHP script to do essentially the same thing (although more elegantly and with more functionality).  Their code is available on Github [3].

Good luck!

- Michael Doran

[1] http://search.cpan.org/dist/RDF-Helper/

[2] Examples of data for UTA Libraries:
    https://worldcat.org/wcr/normal-hours/data/2928
    https://worldcat.org/wcr/special-hours/data/2928

[3] https://github.com/oclc-developer-house/wclibhours

# Michael Doran, Systems Librarian
# University of Texas at Arlington
# 817-272-5326 office
# 817-688-1926 mobile
# [log in to unmask]
# http://rocky.uta.edu/doran/

> -----Original Message-----
> From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of
> Jean Roth
> Sent: Tuesday, September 30, 2014 9:14 AM
> To: [log in to unmask]
> Subject: [CODE4LIB] Python or Perl script for reading RDF/XML, Turtle, or
> N-triples Files
> 
> Thank you so much for the reply.
> 
> I have not investigated the LCNAF data set thoroughly.  However, my
> default/ideal is to read in all variables from a dataset.
> 
> So, I was wondering if any one had an example Python or Perl script for
> reading RDF/XML, Turtle, or N-triples file.  A simple/partial example
> would be fine.
> 
> Thanks,
> 
> Jean
> 
> On Mon, 29 Sep 2014, Kyle Banerjee wrote:
> 
> KB> The best way to handle them depends on what you want to do. You need
> to
> KB> actually download the NAF files rather than countries or other small
> files
> KB> as different kinds of data will be organized differently. Just don't
> try to
> KB> read multigigabyte files in a text editor :)
> KB>
> KB> If you start with one of the giant XML files, the first thing you'll
> KB> probably want to do is extract just the elements that are interesting
> to
> KB> you. A short string parsing or SAX routine in your language of choice
> KB> should let you get the information in a format you like.
> KB>
> KB> If you download the linked data files and you're interested in actual
> KB> headings (as opposed to traversing relationships), grep and sed in
> KB> combination with the join utility are handy for extracting the
> elements you
> KB> want and flattening the relationships into something more convenient
> to
> KB> work with. But there are plenty of other tools that you could also
> use.
> KB>
> KB> If you don't already have a convenient environment to work on, I'm a
> fan
> KB> of virtualbox. You can drag and drop things into and out of your
> regular
> KB> desktop or even access it directly. That way you can view/manipulate
> files
> KB> with the linux utilities without having to deal with a bunch of
> clunky file
> KB> transfer operations involving another machine. Very handy for when
> you have
> KB> to deal with multigigabyte files.
> KB>
> KB> kyle
> KB>
> KB> On Mon, Sep 29, 2014 at 11:19 AM, Jean Roth <[log in to unmask]> wrote:
> KB>
> KB> > Thank you!  It looks like the files are available as  RDF/XML,
> Turtle, or
> KB> > N-triples files.
> KB> >
> KB> > Any examples or suggestions for reading any of these formats?
> KB> >
> KB> > The MARC Countries file is small, 31-79 kb.  I assume a script that
> KB> > would read a small file like that would at least be a start for the
> LCNAF
> KB> >
> KB> >
> KB>



#!/usr/bin/perl

####################################################################
#
#  Michael Doran, University of Texas at Arlington
#  [log in to unmask]
#
#  @ OCLC Developer House
#  February 3-7, 2014
#
#  Proof-of-concept for extracting, parsing, and displaying
#  a library's hours from institutional data in the
#  OCLC WorldCat Registry.
#      see: http://www.worldcat.org/registry/Institutions
#
#  Requires non-core Perl module(s) and CA Root certs file
#
####################################################################

use strict;

####################################################################
# Configuration -- start
####################################################################

# OCLC organization number (not symbol) for main library unit
# aka "Institution Registry ID"
# examples:
#    2928 for University of Texas at Arlington Library
#  128807 for OCLC WorldShare Platform Sandbox Institution

#my $oclc_org_no = '2928';
my $oclc_org_no = '128807';

# Path to SSL Root Certificate Authority bundle file
# - required for HTTPS gets
my $cert_file = '../../ssl.crt/ca-bundle.crt';

# Labels for normal and special hours display
my $normal_hrs_label  = 'REGULAR HOURS';
my $special_hrs_label = 'SPECIAL HOURS';

####################################################################
# Configuration -- end 
####################################################################

# Required modules
use LWP::UserAgent;
use RDF::Helper;
#use Date::Calc;    # Not used yet, but needed for further development

my $oclc_org_base_url = "https://www.worldcat.org/wcr/organization/resource/$oclc_org_no";
my $content           = '';
my $normal_hours_uri  = '';
my $normal_hours_rdf  = '';
my $special_hours_uri = '';
my $special_hours_rdf = '';
my $null              = undef;

my $ua = LWP::UserAgent->new;
   $ua->timeout(10);
   $ua->default_header('Accept' => 'application/rdf+xml');
   $ua->ssl_opts( SSL_ca_file => "$cert_file" );
 
my $rdf = RDF::Helper->new(
    BaseInterface => 'RDF::Trine',
    namespaces => {
        rdf     => "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
        wcir    => "http://purl.org/oclc/ontology/wcir/",
        schema  => "http://schema.org/",
        rdfs    => "http://www.w3.org/2000/01/rdf-schema#",
        umbel   => "http://umbel.org/umbel#",
        foaf    => "http://xmlns.com/foaf/0.1/",
        library => "http://purl.org/library/",
        xsi     => "http://www.w3.org/2001/XMLSchema-instance",
        dcterms => "http://purl.org/dc/terms/"
    },
    ExpandQNames => 1
);

GetInstData();

NormalHours($normal_hours_uri);

SpecialHours($special_hours_uri);

exit(0);

#########################
#  GetRDFDoc 
#########################

sub GetRDFDoc {
    my ($uri) = @_;
    my $response = $ua->get("$uri");
    if ($response->is_success) {
        $content = $response->decoded_content;
    }
    else {
        die $response->status_line;
    }
}

#########################
#  GetInstData 
#########################

sub GetInstData {
    GetRDFDoc("$oclc_org_base_url");

    $rdf->include_rdfxml(xml => $content);

    my $hash_ref = $rdf->tied_property_hash($oclc_org_base_url);
    my %prop_value_hash = %$hash_ref;

    my $institution = $prop_value_hash{'wcir:institutionName'};
    my $library     = $prop_value_hash{'wcir:unitName'};
    $normal_hours_uri  = $prop_value_hash{'wcir:normalHours'};
    $special_hours_uri = $prop_value_hash{'wcir:specialHours'};

    print "\n" . "$institution" . "\n"; 

    if ($library) {
        print "$library" . "\n"; 
    }
}

#########################
#  NormalHours
#########################

sub NormalHours {
    my ($normal_hours_uri) = @_;
    unless ($normal_hours_uri) {
        return;
    } 
    print "\n" . "$normal_hrs_label" . "\n\n";
    $normal_hours_rdf = GetRDFDoc("$normal_hours_uri");
    $rdf->include_rdfxml(xml => $normal_hours_rdf);
    my $norm_hours_hash_ref = $rdf->tied_property_hash($normal_hours_uri);
    my %norm_value_hash = %$norm_hours_hash_ref;
    foreach my $week_day ('Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday') {
       my $day_hash_ref = $rdf->tied_property_hash("$normal_hours_uri#$week_day");
       my %day_hash = %$day_hash_ref;
       my $open_status   = $day_hash{'wcir:openStatus'};
       my $open_hour     = $day_hash{'wcir:opens'};
       my $close_hour     = $day_hash{'wcir:closes'};
       if ($open_status eq "Open24Hours") {
           print "$week_day open 24 hours" . "\n";
       } elsif ($open_status eq "Open") {
           print "$week_day open from $open_hour to $close_hour" . "\n";
       } elsif ($open_status eq "Closed") {
           print "$week_day is closed" . "\n";
       }
    }
}

#########################
#  SpecialHours
#########################

sub SpecialHours {
    unless ($special_hours_uri) {
        return;
    } 
    print "\n" . "$special_hrs_label" . "\n";
    $special_hours_rdf = GetRDFDoc ("$special_hours_uri");
    $rdf->include_rdfxml(xml => $special_hours_rdf);
    my $spec_hours_hash_ref = $rdf->tied_property_hash($special_hours_uri);
    my %spec_value_hash = %$spec_hours_hash_ref;

    # problem area here - fixed
    #  - when single value returned to $hoursSpecs, can't dereference
    #  - if don't deference, can't handle when it is an array reference returned,
    #     e.g. ARRAY(0x7fd4c2b34f40)
    # Solution: test with perl 'ref' function
    my $hoursSpecs = $spec_value_hash{'wcir:hoursSpecifiedBy'};
    my @deref_hoursSpecs;
    if (ref($hoursSpecs)) {
        @deref_hoursSpecs = @$hoursSpecs;
    } else {
        @deref_hoursSpecs = $hoursSpecs;
    }

    my %spec_hours_instances;
    foreach my $i (@deref_hoursSpecs) {
        my $day_hash_ref = $rdf->tied_property_hash("$i");
        my %day_hash = %$day_hash_ref;
        my $valid_from     = $day_hash{'wcir:validFrom'};
        $spec_hours_instances{$valid_from} = $i;
    }
    foreach my $key (sort keys %spec_hours_instances) {
        print "\n";
        my $day_hash_ref = $rdf->tied_property_hash("$spec_hours_instances{$key}");
        my %day_hash = %$day_hash_ref;
        my $description  = $day_hash{'wcir:description'};
        my $open_status  = $day_hash{'wcir:openStatus'};
        my $open_hour    = $day_hash{'wcir:opens'};
        my $close_hour   = $day_hash{'wcir:closes'};
        my $valid_from   = $day_hash{'wcir:validFrom'};
        my $valid_to     = $day_hash{'wcir:validTo'};
        print "$description" . "\n";
        if ($open_status eq "Open24Hours") {
            print "Open 24 hours" . "\n";
        } elsif ($open_status eq "Open") {
           print "Open from $open_hour to $close_hour" . "\n";
        } elsif ($open_status eq "Closed") {
           print "Closed" . "\n";
        }
        print "From $valid_from to $valid_to" . "\n";
    }
}