Generic simple SPARQL interface for Python v3.

pysparql3.py

#!/usr/bin/env python
import http, json, base64
from urllib.request import Request, urlopen
from urllib.parse import urlencode
from urllib.error import HTTPError
from time import time

class PySparql():

    def __init__(this, endpoint, username=None, password=None, buffer_size=10000):
        this.buffer_size = buffer_size
        this.endpoint = endpoint
        this.username = username
        this.password = password
        this.param = {
            # "format": "JSON",
            # "CXML_redir_for_subjs": "121",
            # "CXML_redir_for_hrefs": "",
            # "timeout": "600000",
            # "debug": "on",
        }

    def query(this, query, graph=""):

        t0 = time()
        res = this._query_all(query, graph)
        dt = time() - t0
        dt_str = "%f" % dt
        # print(u"QUERYTIME\t{}\t{}".format(dt_str, query.encode('utf-8')))
        return res

    def _query_all(this, query, graph):
        results = []
        i = 0
        while(True):
            offset = i * this.buffer_size
            part = this._query_buffer("{} OFFSET {} LIMIT {}".format(query, offset, this.buffer_size), graph)
            results += part
            if len(part) < this.buffer_size:
                break
            i += 1
        return results

    def _query_buffer(this, query, graph):

        this.param["default-graph-uri"] = graph
        this.param["query"] = query.encode('utf-8')
        #print(query)
        try:
            headers = {'Accept': 'application/json'}
            if this.username is not None and this.password is not None:
                headers['Authorization'] = "Basic {}".format(base64.b64encode("{}:{}".format(this.username, this.password)))
            #print(headers)
            req = Request(this.endpoint + "?" + urlencode(this.param), None, headers)
            resp = urlopen(req)
            j = resp.read()
            resp.close()
            return json.loads(j)['results']['bindings']
        except (HTTPError, http.client.BadStatusLine) as error:
            j = '{ "results": { "bindings": [] } }'
            print(error)
            return []