如何在owlready2中获取对象属性的comment注释？

问题场景 #

使用OWLready2处理OWL本体的对象属性时，通过点属性可正常获取label、isDefinedBy等注释，但调用property.comment始终返回空列表，尽管目标属性在OWL文件中明确包含rdfs:comment断言。

代码示例 #

>>> print(property.name)
actsFor
>>> print(property.label)
[locstr('acts for', 'en'), locstr('agisce per', 'it')]
>>> print(property.comment)
[]

对应OWL片段 #

<!-- http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#actsFor -->

<owl:ObjectProperty rdf:about="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#actsFor">
    <rdfs:subPropertyOf rdf:resource="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#associatedWith"/>
    <owl:inverseOf rdf:resource="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#actsThrough"/>
    <rdfs:domain rdf:resource="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#Agent"/>
    <rdfs:range rdf:resource="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl#SocialAgent"/>
    <rdfs:comment>The relation holding between any Agent, and a SocialAgent. In principle, a SocialAgent requires at least one PhysicalAgent in order to act, but this dependency can be &apos;delegated&apos;; e.g. a university can be acted for by a department, which on its turm is acted for by physical agents.</rdfs:comment>
    <rdfs:isDefinedBy rdf:resource="http://www.ontologydesignpatterns.org/ont/dul/DUL.owl"/>
    <rdfs:label xml:lang="en">acts for</rdfs:label>
    <rdfs:label xml:lang="it">agisce per</rdfs:label>
</owl:ObjectProperty>

解决方法 #

OWLready2默认仅为部分常用RDFS注释属性（如label、isDefinedBy）创建了直接的Python点属性映射，rdfs:comment不在默认映射范围内，可通过以下两种方式获取：

方法1：手动绑定属性映射 #

将rdfs:comment注释属性绑定到ObjectProperty类的comment属性，之后即可通过点属性直接访问：

from owlready2 import *

# 加载目标本体
onto = get_ontology("http://www.ontologydesignpatterns.org/ont/dul/DUL.owl").load()

# 获取rdfs:comment注释属性
rdfs_comment = onto.get_annotation_property("http://www.w3.org/2000/01/rdf-schema#comment")

# 绑定到ObjectProperty类的comment属性
ObjectProperty.comment = rdfs_comment

# 之后即可正常访问
property = onto.actsFor
print(property.comment)

方法2：使用通用注释获取方法 #

无需绑定，直接通过get_annotations方法或遍历annotations属性筛选指定注释：

from owlready2 import *

onto = get_ontology("http://www.ontologydesignpatterns.org/ont/dul/DUL.owl").load()
rdfs_comment = onto.get_annotation_property("http://www.w3.org/2000/01/rdf-schema#comment")
property = onto.actsFor

# 方式1：使用get_annotations批量获取
comments = property.get_annotations(rdfs_comment)
print([anno.value for anno in comments])

# 方式2：遍历所有注释筛选
for anno in property.annotations:
    if anno.property == rdfs_comment:
        print(anno.value)

内容的提问来源于stack exchange，提问作者Xin Feng