Source code for rdflib.plugins.sparql.results.txtresults

from typing import IO, List, Optional
from rdflib import URIRef, BNode, Literal
from rdflib.query import ResultSerializer
from rdflib.namespace import NamespaceManager
from rdflib.term import Variable


def _termString(t, namespace_manager: Optional[NamespaceManager]):
    if t is None:
        return "-"
    if namespace_manager:
        if isinstance(t, URIRef):
            return namespace_manager.normalizeUri(t)
        elif isinstance(t, BNode):
            return t.n3()
        elif isinstance(t, Literal):
            return t._literal_n3(qname_callback=namespace_manager.normalizeUri)
    else:
        return t.n3()


[docs]class TXTResultSerializer(ResultSerializer): """ A write only QueryResult serializer for text/ascii tables """ # TODO FIXME: class specific args should be keyword only.
[docs] def serialize( # type: ignore[override] self, stream: IO, encoding: str, namespace_manager: Optional[NamespaceManager] = None, ): """ return a text table of query results """ def c(s, w): """ center the string s in w wide string """ w -= len(s) h1 = h2 = w // 2 if w % 2: h2 += 1 return " " * h1 + s + " " * h2 if self.result.type != "SELECT": raise Exception("Can only pretty print SELECT results!") if not self.result: return "(no results)\n" else: keys: List[Variable] = self.result.vars # type: ignore[assignment] maxlen = [0] * len(keys) b = [ [_termString(r[k], namespace_manager) for k in keys] for r in self.result ] for r in b: for i in range(len(keys)): maxlen[i] = max(maxlen[i], len(r[i])) stream.write("|".join([c(k, maxlen[i]) for i, k in enumerate(keys)]) + "\n") stream.write("-" * (len(maxlen) + sum(maxlen)) + "\n") for r in sorted(b): stream.write( "|".join([t + " " * (i - len(t)) for i, t in zip(maxlen, r)]) + "\n" )