構建三元組後，需要對圖進行儲存到本地，並進行讀取

程式碼示例：

1. 利用sleepycat進行rdf資料持久化

#coding:utf8
import rdflib

graph = rdflib.Graph('Sleepycat', identifier='lhq')

# first time create the store:
graph.open('db', create=True)

# work with the graph:
s = rdflib.URIRef('牛膝')
p = rdflib.URIRef('功效屬性')
o = rdflib.URIRef('活血')

graph.add((s, p, o))

# when done!
graph.close()

g_t = rdflib.Graph('Sleepycat', identifier='lhq') # 新建圖，指定資料庫
g_t.open('db') # 開啟資料庫並進行操作
print len(g_t)
g_t.close()
 

2.利用serialize將資料以一定規範儲存到硬碟中

主要用到了兩個函式

serialize：將資料序列化儲存到本地

<span style="font-size:18px;">serialize(destination=None, format='xml', base=None, encoding=None, **args)
Serialize the Graph to destination
將圖序列化到指定地點
If destination is None serialize method returns the serialization as a string. Format defaults to xml (AKA rdf/xml).
如果該處為空，則返回一個字串。預設格式為xml(AKA rdf/xml)
Format support can be extended with plugins, but ‘xml’, ‘n3’, ‘turtle’, ‘nt’, ‘pretty-xml’, trix’ are built in.<span style="font-family: Arial, Helvetica, sans-serif;">支援的格式可以利用外掛進行擴充套件，但‘xml’，‘n3’，‘turtle’，‘nt’，‘pretty-xml’，‘trix’已經被建立了</span>
 

parse：解析本地檔案，讀取資料

<span style="font-size:18px;">parse(source=None, publicID=None, format='xml', location=None, file=None, data=None, **args)[source]
Parse source adding the resulting triples to its own context (sub graph of this graph).
解析源資料並將三元組新增到圖中
See rdflib.graph.Graph.parse() for documentation on arguments.

Returns:	
The graph into which the source was parsed. In the case of n3 it returns the root context.</span>
 

#coding:utf8
import rdflib

# graph = rdflib.Graph('Sleepycat')

#first time create the store:
# graph.open('myRDFLibStore.rdf', create = True)

graph = rdflib.Graph()

s = rdflib.URIRef('牛膝')
p = rdflib.URIRef('功效屬性')
o = rdflib.URIRef('活血')

graph.add((s, p, o))
# 以n3格式儲存
graph.serialize('zhongyao.rdf', format='n3')

s = rdflib.URIRef('http://www.example.org/牛膝')
p = rdflib.URIRef('http://www.example.org/功效屬性')
o = rdflib.URIRef('http://www.example.org/活血')

g1 = rdflib.Graph()
g1.add((s, p, o))
g1.serialize('zhongyao1.rdf') # 預設以'xml'格式儲存

g2 = rdflib.Graph()
g2.parse('zhongyao1.rdf', format='xml') # 解析rdf檔案時，需要指定格式
subject = g2.subjects(p, o)
for i in subject:
	print i