This library generates invalid turtle output

[wetneb]

This library generates invalid turtle output:

<http://www.cse.iitb.ac.in/~soumen/doc/CSAW/doc/yn_08Oct08_file_0/#offset_196_202>
        a                       nif:OffsetBasedString , nif:Phrase ;
        nif:anchorOf            "the famous "covfefe" tweet" ;
        nif:beginIndex          "196"^^xsd:nonNegativeInteger ;
        nif:endIndex            "222"^^xsd:nonNegativeInteger ;
        nif:referenceContext    <http://www.cse.iitb.ac.in/~soumen/doc/CSAW/doc/yn_08Oct08_file_0/#offset_0_1413> ;
        itsrdf:taClassRef        ;
        itsrdf:taConfidence     "1^^xsd:double ;
        itsrdf:taIdentRef       <http://dbpedia.org/resource/Almost> .

The following problems are present

• "1^^xsd:double is missing a double quote
• nif:anchorOf "the famous "covfefe" tweet" ; is missing escaping

There are other problems in context serialization.

<http://www.cse.iitb.ac.in/~soumen/doc/CSAW/doc/yn_08Oct08_file_0/#collection>
        a               nif:ContextCollection ;
        nif:hasContext  <http://www.cse.iitb.ac.in/~soumen/doc/CSAW/doc/yn_08Oct08_file_0/#offset_0_1413>
        <http://purl.org/dc/terms/conformsTo>
                <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core/2.1> .      

a ; is missing after the nif:hasContext statement.

In other words this library is currently unusable.

[wetneb]

I have made a fork at https://github.com/wetneb/pynif which solves this issue (among others).