PyShExC - The Python ShExC Parser
This package converts the Shape Expression Compact (ShExC) into Python JSON Schema Binding (pyjsg) objects. The pyjsg object representation can be used to:
- Produce equivalent ShEx definitions in ShEx JSON (ShExJ) notation
- Produce equivalent ShEx definitions in ShEx RDF (ShExR) notation
- Implement a Python ShEx interpreter
History
- 0.4.0 -- Almost ready for 2.1 release. 9 test errors remain, all involving unicode
- 0.4.1 -- Added contextcache. See test_shexr for how to use
- 0.4.2 -- Tweaks in 4 and 8 byte unicode parsing
- 0.5.0 -- Passes all 2.1 tests
- 0.5.1 -- Fix requirements
- 0.5.2 -- Add URL fetch ability and fix UTF8-BOM issue
- 0.5.3 -- Factor out fetch ability for re-use in other packages
- 0.5.4 -- Fix to 0.5.2 -- low probability type matches have to be ignored
Installation
> pip install PyShExCUsage
Command Line
usage: shexc_to_shexj [-h] [-nj] [-nr] [-j JSONFILE] [-r RDFFILE]
[--context CONTEXT]
[-f {trix,trig,ttl,n3,turtle,ntriples,xml,json-ld,nt11,pretty-xml,nquads,nt}]
infile
positional arguments:
infile Input ShExC specification
optional arguments:
-h, --help show this help message and exit
-nj, --nojson Do not produce json output
-nr, --nordf Do not produce rdf output
-j JSONFILE, --jsonfile JSONFILE
Output ShExJ file (Default: {infile}.json)
-r RDFFILE, --rdffile RDFFILE
Output ShExR file (Default: {infile}.{fmt suffix})
--context CONTEXT Alternative @context for json to RDF
-f {trix,trig,ttl,n3,turtle,ntriples,xml,json-ld,nt11,pretty-xml,nquads,nt}, --format {trix,trig,ttl,n3,turtle,ntriples,xml,json-ld,nt11,pretty-xml,nquads,nt}
Output format (Default: turtle)
> wget https://raw.githubusercontent.com/shexSpec/shexTest/master/schemas/FocusIRI2groupBnodeNested2groupIRIRef.shex -O test.shex
> shexc_to_shexj test.shex --context shex.jsonld
JSON output written to test.json
turtle output written to test.ttltest.shex
<http://a.example/S1> IRI /^https?:\/\// {
<http://a.example/p1> <http://a.example/dt1> ;
<http://a.example/p2> BNODE {
<http://a.example/p3> LITERAL ;
<http://a.example/p4> IRI /^https?:\/\// @<http://a.example/S1>?
} AND CLOSED { <http://a.example/p3> . ; <http://a.example/p4> . }
}
test.json
{
"type": "Schema",
"@context": "http://www.w3.org/ns/shex.jsonld",
"shapes": [
{
"type": "ShapeAnd",
"id": "http://a.example/S1",
"shapeExprs": [
{
"type": "NodeConstraint",
"nodeKind": "iri",
"pattern": "^https?://"
},
{
"type": "Shape",
"expression": {
"type": "EachOf",
"expressions": [
{
"type": "TripleConstraint",
"predicate": "http://a.example/p1",
"valueExpr": {
"type": "NodeConstraint",
"datatype": "http://a.example/dt1"
}
},
{
"type": "TripleConstraint",
"predicate": "http://a.example/p2",
"valueExpr": {
"type": "ShapeAnd",
"shapeExprs": [
{
"type": "ShapeAnd",
"shapeExprs": [
{
"type": "NodeConstraint",
"nodeKind": "bnode"
},
{
"type": "Shape",
"expression": {
"type": "EachOf",
"expressions": [
{
"type": "TripleConstraint",
"predicate": "http://a.example/p3",
"valueExpr": {
"type": "NodeConstraint",
"nodeKind": "literal"
}
},
{
"type": "TripleConstraint",
"predicate": "http://a.example/p4",
"valueExpr": {
"type": "ShapeAnd",
"shapeExprs": [
{
"type": "NodeConstraint",
"nodeKind": "iri",
"pattern": "^https?://"
},
"http://a.example/S1"
]
},
"min": 0,
"max": 1
}
]
}
}
]
},
{
"type": "Shape",
"closed": "true",
"expression": {
"type": "EachOf",
"expressions": [
{
"type": "TripleConstraint",
"predicate": "http://a.example/p3"
},
{
"type": "TripleConstraint",
"predicate": "http://a.example/p4"
}
]
}
}
]
}
}
]
}
}
]
}
]
}test.ttl
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix shex: <http://www.w3.org/ns/shex#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
<http://a.example/S1> a shex:ShapeAnd ;
shex:shapeExprs ( [ a shex:NodeConstraint ;
shex:nodeKind shex:iri ;
shex:pattern "^https?://" ] [ a shex:Shape ;
shex:expression [ a shex:EachOf ;
shex:expressions ( [ a shex:TripleConstraint ;
shex:predicate <http://a.example/p1> ;
shex:valueExpr [ a shex:NodeConstraint ;
shex:datatype <http://a.example/dt1> ] ] [ a shex:TripleConstraint ;
shex:predicate <http://a.example/p2> ;
shex:valueExpr [ a shex:ShapeAnd ;
shex:shapeExprs ( [ a shex:ShapeAnd ;
shex:shapeExprs ( [ a shex:NodeConstraint ;
shex:nodeKind shex:bnode ] [ a shex:Shape ;
shex:expression [ a shex:EachOf ;
shex:expressions ( [ a shex:TripleConstraint ;
shex:predicate <http://a.example/p3> ;
shex:valueExpr [ a shex:NodeConstraint ;
shex:nodeKind shex:literal ] ] [ a shex:TripleConstraint ;
shex:max 1 ;
shex:min 0 ;
shex:predicate <http://a.example/p4> ;
shex:valueExpr [ a shex:ShapeAnd ;
shex:shapeExprs ( [ a shex:NodeConstraint ;
shex:nodeKind shex:iri ;
shex:pattern "^https?://" ] <http://a.example/S1> ) ] ] ) ] ] ) ] [ a shex:Shape ;
shex:closed true ;
shex:expression [ a shex:EachOf ;
shex:expressions ( [ a shex:TripleConstraint ;
shex:predicate <http://a.example/p3> ] [ a shex:TripleConstraint ;
shex:predicate <http://a.example/p4> ] ) ] ] ) ] ] ) ] ] ) .
[] a shex:Schema ;
shex:shapes <http://a.example/S1> .
