String xsd:double value crash toRrdf()

[anatoly-scherbakov]

Why

Here's a JSON-LD document.

{
  "@context": {
    "xsd": "http://www.w3.org/2001/XMLSchema#",
    "geoLongitude": "http://www.w3.org/2003/01/geo/wgs84_pos#longitude"
  },
  "@graph": [
    {
      "@id": "http://www.wikidata.org/entity/Q399",
      "geoLongitude": {
        "@type": "xsd:double",
        "@value": "45"
      }
    }
  ]
}

Conversion of this document to a RDF dataset works at JSON-LD playground, but it will crash pyld 2.0.4:

    def _object_to_rdf(self, item, issuer, triples, rdfDirection):
        """
        Converts a JSON-LD value object to an RDF literal or a JSON-LD string
        or node object to an RDF resource.
    
        :param item: the JSON-LD value or node object.
        :param issuer: the IdentifierIssuer for issuing blank node identifiers.
        :param triples: the array of triples to append list entries to.
        :param rdfDirection: for creating datatyped literals.
        :param rdfDirection: for creating datatyped literals.
    
        :return: the RDF literal or RDF resource.
        """
        object = {}
    
        if _is_value(item):
            object['type'] = 'literal'
            value = item['@value']
            datatype = item.get('@type')
    
            # convert to XSD datatypes as appropriate
            if item.get('@type') == '@json':
                object['value'] = canonicalize(value).decode('UTF-8')
                object['datatype'] = RDF_JSON_LITERAL
            elif _is_bool(value):
                object['value'] = 'true' if value else 'false'
                object['datatype'] = datatype or XSD_BOOLEAN
            elif _is_double(value) or datatype == XSD_DOUBLE:
                # canonical double representation
                object['value'] = re.sub(
                    r'(\d)0*E\+?0*(\d)', r'\1E\2',
>                   ('%1.15E' % value))
E               TypeError: must be real number, not str

What

This PR

• Creates a unit test demonstrating the problem,
• Contains a fix to it.

[anatoly-scherbakov]

@BigBlueHat @davidlehn please let me know what you think. Thanks!