如何解决owlready2中SPARQL语言过滤返回空集的问题？

问题描述 #

我在Google云端硬盘的“Quran Corpus”文件夹中存储了本体文件quran_data_full.owl。在Apache Jena Fuseki中执行SPARQL查询能得到正确的阿拉伯语结果，但把查询复制到Google Colab的Owlready2代码中后，加入FILTER langMatches(lang(?text),"ar")语句就返回空集；删除该语句能返回包含阿拉伯语和英语的结果，我需要仅显示阿拉伯语文本。

原代码如下：

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")
}
"""))

解决方案 #

• 确认实际语言标签格式：Owlready2对语言标签的解析逻辑和Jena Fuseki存在差异，先执行查询查看本体中rdfs:label实际存储的语言代码，比如是否带区域后缀（如ar-SA）或大小写不一致。
• 调整过滤条件：如果实际语言标签是标准的ar，可替换langMatches为直接匹配FILTER(lang(?text) = "ar")；如果是带区域的标签，保留langMatches(lang(?text), "ar")即可兼容匹配。

修改后的代码示例 #

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/")

# 第一步：查询所有相关文本的实际语言标签
lang_check = list(default_world.sparql("""
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX qur: <http://quranontology.com/Resource/>
SELECT ?text (lang(?text) AS ?lang)
WHERE {?verse rdf:type qur:Verse.
?verse qur:DiscussTopic ?topic.
?verse rdfs:label ?text.
?topic qur:TopicCompleteName ?topicName.
FILTER (REGEX(STR(?topicName), "زكاة" ,"i")).
}
"""))
print("实际语言标签：", lang_check)

# 第二步：根据查询到的语言标签调整过滤条件
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")).
# 根据实际查询结果修改，比如匹配标准ar标签
FILTER(lang(?text) = "ar")
}
"""))

内容的提问来源于stack exchange，提问作者Reem