rdflib查询sparql导致FILTER键解析错误。

Question

我试图用rdflib对一个图形运行一个SPARQL查询。如果我没有使用FILTER，它工作得很好，否则它在将字符串解析为查询时就会导致错误。我使用的是PYTHON 2.7。. 看了别人的查询，我看不到任何语法错误。

 query = " SELECT ?textspan WHERE " \
             " { ?textspan rst:startOffset ?start ; " \
             "                    rst:endOffset ?end . " \
             "    FILTER ( ?start <= "+denotedStartOffset+" < ?end ) } " 

他们与。

 query = " SELECT ?textspan WHERE " \
             " { ?textspan rst:startOffset ?start ; " \
             "                    rst:endOffset ?end . " \
             "    FILTER ( ?start <= 5 < ?end ) } " 

错误。

Traceback (most recent call last):
  File "link.py", line 27, in <module>
    qres = g.query(QUERY_2)
  File "/usr/local/lib/python2.7/dist-packages/rdflib/graph.py", line 1085, in query
    query_object, initBindings, initNs, **kwargs))
  File "/usr/local/lib/python2.7/dist-packages/rdflib/plugins/sparql/processor.py", line 74, in query
    parsetree = parseQuery(strOrQuery)
  File "/usr/local/lib/python2.7/dist-packages/rdflib/plugins/sparql/parser.py", line 1058, in parseQuery
    return Query.parseString(q, parseAll=True)
  File "/usr/local/lib/python2.7/dist-packages/pyparsing.py", line 1947, in parseString
    raise exc
pyparsing.ParseException: Expected {SelectQuery | ConstructQuery | DescribeQuery | AskQuery}, found u'F'  (at char 103), (line:1, col:104)

它说它不期望'F'，所以它不认识FILTER。

Answer 1

正如@不知情的用户所建议的解决方法是什么？FILTER ( ?start <= 5 && 5 < ?end )