使用python的rdflib,我可以解析SPARQL查询字符串,并使用以下语法转换其代数形式:
statement = "Select ?s ?p ?o where {?s ?p ?o.}"
query_tree = parser.parseQuery(statement) # query parse-tree
q_algebra = algebra.translateQuery(query_tree) # query algebra
algebra.pprintAlgebra(q_algebra)上面查询的代数树如下所示:
SelectQuery(
p = Project(
p = BGP(
triples = [(rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o'))]
_vars = {rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o')}
)
PV = [rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o')]
_vars = {rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o')}
)
datasetClause = None
PV = [rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o')]
_vars = {rdflib.term.Variable('s'), rdflib.term.Variable('p'), rdflib.term.Variable('o')}
)在通过使用algebra.traverse(q_algebra, update_function)更新查询代数之后,我想再次获得查询字符串。我通过rdflib模块悄悄地搜索了很多,但找不到如何反向翻译代数的方法。是否有一个函数可以将SPARQL查询代数作为输入并返回SPARQL查询字符串?
发布于 2021-07-15 20:07:08
不,感谢Greenfish自己在https://github.com/RDFLib/rdflib/pull/1322的rdflib6.0.0中提供了这个功能
https://stackoverflow.com/questions/67384151
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