使用owlready2执行SPARQL查询时出现MinusBlock类型未知错误的解决方法

问题情况 #

在Google Drive的Quran Corpus文件夹中存储了本体文件quran_data_full.owl，该本体的SPARQL查询在Apache Jena Fuseki上能正常运行并返回正确结果，但将相同查询复制到Google Colab的owlready2代码中时，触发了与MinusBlock相关的ValueError。

原代码 #

from owlready2 import *
onto_path.append("/gdrive/MyDrive/Quran Corpus")
go = get_ontology("/gdrive/MyDrive/Quran Corpus/quran_data_full.owl").load()
obo = get_namespace("/gdrive/MyDrive/Quran Corpus/")
d = list(default_world.sparql("""
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX qur: <http://quranontology.com/Resource/>
SELECT ?verse ?text 
WHERE {?verse rdf:type qur:Verse.
?verse qur:DiscussTopic ?topic.
?verse rdfs:label ?text.
?topic qur:TopicCompleteName ?topicName.
FILTER (REGEX(STR(?topicName), "زكاة" ,"i")).
FILTER langMatches(lang(?text),"ar")
MINUS { ?verse rdfs:label ?text.
FILTER (REGEX(STR(?text), "زكاة" ,"i")).} 
}
"""))

报错信息 #

ValueError: Unknown block type '<MinusBlock [(VAR:'?verse', IRI:'http://www.w3.org/2000/01/rdf-schema#label', VAR:'?text'), <owlready2.sparql.parser.Filter object at 0x7f8b5a75b970>]>'!

报错原因 #

Owlready2的内置SPARQL解析器不支持MINUS子句，它仅实现了SPARQL规范的核心子集，和Jena Fuseki这种完整支持SPARQL标准的引擎存在功能差异。

解决方案 #

将MINUS子句替换为FILTER NOT EXISTS，二者在当前查询场景下功能完全等价，且Owlready2支持FILTER NOT EXISTS语法。

修改后的代码 #

from owlready2 import *
onto_path.append("/gdrive/MyDrive/Quran Corpus")
go = get_ontology("/gdrive/MyDrive/Quran Corpus/quran_data_full.owl").load()
obo = get_namespace("/gdrive/MyDrive/Quran Corpus/")
d = list(default_world.sparql("""
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX qur: <http://quranontology.com/Resource/>
SELECT ?verse ?text 
WHERE {
    ?verse rdf:type qur:Verse.
    ?verse qur:DiscussTopic ?topic.
    ?verse rdfs:label ?text.
    ?topic qur:TopicCompleteName ?topicName.
    FILTER (REGEX(STR(?topicName), "زكاة" ,"i")).
    FILTER langMatches(lang(?text),"ar")
    FILTER NOT EXISTS { 
        ?verse rdfs:label ?text.
        FILTER (REGEX(STR(?text), "زكاة" ,"i")).
    } 
}
"""))

内容的提问来源于stack exchange，提问作者Reem