轻量级RDF流解析器
项目描述
Python轻量级RDF流解析器
一个轻量级的RDF和RDF-Star解析器,可以直接从磁盘或标准输入流中流式传输三元组,而无需将整个图加载到内存中。
支持N-Triples和N-Quads序列化格式。
用法
读取和写入磁盘。
from rdf import NTriples
from rdf import Literal
with NTriples(path = "./pizzacats.nt", mode = 'r') as g:
with NTriples(path = "./out.nt", mode = 'w') as h:
for subject, predicate, object in g.parse():
if type(object) is Literal and object.language == "en":
# do stuff
h.write((subject, predicate, object))
从标准输入/输出读取/写入。
from os import stdin
from rdf import NQuads
from rdf import IRIRef
g = NQuads(data=stdin.read(), mode = 'r')
h = NQuads(mode = 'w')
target = IRIRef("https://example.org/Pizzacat")
for triple in g.parse():
if triple[0] == target: # subject
# do stuff
h.write(triple)
g.close()
h.close()
添加新的三元组。
from rdf import IRIRef, Literal, Statement
from rdf import RDF, XSD
EX = IRIRef("https://example.org/") # define prefix
g = set()
subject = EX + "Pizzacat"
g.add(Statement(subject, RDF+"type", EX+"Cat"))
literal = Literal("Samurai Pizza Cats!!!", datatype=XSD+"string")
g.add(Statement(subject, EX+"tag_phrase", literal))