使用IPython Notebook（使用rdflib？）来记录SPARQL查询和结果(Using IPython Notebook (with rdflib?) to log SPARQL queries and results)

 我想使用IPython Notebook记录SPARQL查询以及这些查询的结果。 
 
 由于任何命令行工具都可以通过“bang”从IPython Notebook调用，我当然可以运行： 
 
!arq --data dcterms.ttl --query test1.rq
 
 或者使用roqet，我甚至可以在命令本身中嵌入一个简短的查询： 
 
!roqet -i sparql -e ’SELECT * WHERE { ?s ?p ?o }’ -D dcterms.rdf
 
 arq或roqet都不接受多行SPARQL查询作为参数。 任何长于一行的查询都必须存储在文件中（例如，如上所述的“test1.rq”）。 
 
 更好的方法是直接在IPython Notebook单元中定义SPARQL查询，在那里可以轻松地克隆和调整它们。 以下作品： 
 
In [4]:   myquery = """
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
          CONSTRUCT
          WHERE {?s rdf:type ?o}
          """

In [5]:   def turtleme(myquery):
              import rdflib
              g = rdflib.Graph()
              g.parse('dcam.rdf')
              results = g.query(myquery)
              print results.serialize(format="turtle")

In [6]:   turtleme(myquery)

Out [6]:  @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
          @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
          @prefix xml: <http://www.w3.org/XML/1998/namespace> .
          @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

          <http://purl.org/dc/dcam/VocabularyEncodingScheme> a rdfs:Class .
          <http://purl.org/dc/dcam/memberOf> a rdf:Property .
 
 但是，我没有看到传递指定要查询的数据源的SPARQL查询的方法，例如： 
 
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

          CONSTRUCT
          FROM <dcterms.ttl>
          FROM <dcam.ttl>
          WHERE {?s rdf:type ?o}
 
 或者，至少要改进功能，以便它至少需要一个文件名作为参数，如 
 
        turtleme('dcam.ttl', myquery)
 
 我已经搜索了谷歌的热门搜索，以获得使用带有SPARQL的IPython Notebook但没有找到的例子。 对于专为数据探索而设计的环境而言，这似乎是一个明显的用途 我发现真正有效的唯一方法是运行arq，但是人们需要这样做 
 
        !cat test3.rq
 
 将查询粘贴到IPython Notebook中，它完成了记录数据探索过程的功能，但查询必须与笔记本并行编辑，作为单独的文件。 我的目标是让初学者轻松使用SPARQL探索RDF数据并在笔记本中记录他们的探索。 肯定有更好的办法！ 
 
 更新： 
 
 @Joshua Taylor，@ AndyS指出这些命令接受多行查询作为参数。 这在bash提示符下工作正常，但遗憾的是不在IPython Notebook中，它会抛出一个SyntaxError： 
 
In [5]:   !arq --data dcam.ttl '
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
          PREFIX dcam:    <http://purl.org/dc/dcam/>
          PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>

          SELECT ?s ?p ?o WHERE { ?s ?p ?o . }'

Out [5]:  File "<ipython-input-5-c9328c1c0c64>", line 2
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
                   ^
          SyntaxError: invalid syntax
 
 如果我在第1行中退出行尾，就像在 
 
In [5]:   !arq --data dcam.ttl '\
          ...

Out [5]:  File "<ipython-input-18-313c556abc1d>", line 2
          PREFIX dcam:    <http://purl.org/dc/dcam/>
                    ^
          SyntaxError: invalid syntax
 
 但是，我无法通过转义行的所有末尾来执行整个命令。 
 
 所以问题可能不在于arq和roqet如何在线处理查询，而是如何将arq和roqet命令行传递给IPython Notebook？ 

I want to use IPython Notebook to record SPARQL queries together with the results of those queries.
 
Since any command-line tool can be called from IPython Notebook with a "bang", I can of course run:
 
!arq --data dcterms.ttl --query test1.rq
 
or with roqet, I can even embed a short query in the command itself:
 
!roqet -i sparql -e ’SELECT * WHERE { ?s ?p ?o }’ -D dcterms.rdf
 
Neither arq or roqet accept multi-line SPARQL queries as arguments. Any query longer than a one-liner must be stored in a file (e.g., "test1.rq" as above).
 
Far better would be to define SPARQL queries directly in IPython Notebook cells, where they could easily be cloned and tweaked. The following works:
 
In [4]:   myquery = """
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
          CONSTRUCT
          WHERE {?s rdf:type ?o}
          """

In [5]:   def turtleme(myquery):
              import rdflib
              g = rdflib.Graph()
              g.parse('dcam.rdf')
              results = g.query(myquery)
              print results.serialize(format="turtle")

In [6]:   turtleme(myquery)

Out [6]:  @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
          @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
          @prefix xml: <http://www.w3.org/XML/1998/namespace> .
          @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

          <http://purl.org/dc/dcam/VocabularyEncodingScheme> a rdfs:Class .
          <http://purl.org/dc/dcam/memberOf> a rdf:Property .
 
However, I do not see a way to pass a SPARQL query that specifies the data sources to be queried, such as:
 
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

          CONSTRUCT
          FROM <dcterms.ttl>
          FROM <dcam.ttl>
          WHERE {?s rdf:type ?o}
 
or, at a minimum, to improve the function so that it will take at least one filename as an argument, as in 
 
        turtleme('dcam.ttl', myquery)
 
I have scoured Google hits for examples of using IPython Notebook with SPARQL but find none. It seems like an obvious use for an environment designed for data exploration. The only method I have found that really works is to run arq, but then one needs to do
 
        !cat test3.rq
 
to paste the query into IPython Notebook, which fulfills the function of documenting the process of exploring data, but queries must all be edited, in parallel to the notebook, as separate files. My objective is to make it easy for beginning students to explore RDF data using SPARQL and record their explorations in the notebook. There must be a better way!
 
UPDATE:
 
@Joshua Taylor, @AndyS point out that the commands accept multiline queries as arguments. This works fine at the bash prompt but unfortunately not in IPython Notebook, which throws a SyntaxError:
 
In [5]:   !arq --data dcam.ttl '
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
          PREFIX dcam:    <http://purl.org/dc/dcam/>
          PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>

          SELECT ?s ?p ?o WHERE { ?s ?p ?o . }'

Out [5]:  File "<ipython-input-5-c9328c1c0c64>", line 2
          PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
                   ^
          SyntaxError: invalid syntax
 
If I escape the end of line in line 1, as in
 
In [5]:   !arq --data dcam.ttl '\
          ...

Out [5]:  File "<ipython-input-18-313c556abc1d>", line 2
          PREFIX dcam:    <http://purl.org/dc/dcam/>
                    ^
          SyntaxError: invalid syntax
 
However, I cannot get the entire command to execute by escaping all of the ends of line.
 
So perhaps the problem lies not with how arq and roqet handle queries in-line but with how those arq and roqet command lines get passed to IPython Notebook?

原文：