Google Knowledge Graph Search API

借助 Knowledge Graph Search API，您可以在 Google 知识图谱中查找实体。该 API 使用标准的 schema.org 类型，并符合 JSON-LD 规范。

典型使用场景

以下示例说明了如何使用 Knowledge Graph Search API：

  • 获取符合特定条件的最著名实体的排名列表。
  • 预测性地填写搜索框中的实体。
  • 使用知识图谱实体为内容添加注释/整理内容。

如需详细了解 API 方法和参数，请参阅 API 参考文档。

示例请求

以下示例展示了您可以发送到 API 的一类请求。（不过请先查看前提条件部分。 您还需要插入自己的 API 密钥。）

https://kgsearch.googleapis.com/v1/entities:search?query=taylor+swift&key=API_KEY&limit=1&indent=True

上面的示例搜索会返回类似于以下内容的 JSON-LD 结果：

{
  "@context": {
    "@vocab": "http://schema.org/",
    "goog": "http://schema.googleapis.com/",
    "resultScore": "goog:resultScore",
    "detailedDescription": "goog:detailedDescription",
    "EntitySearchResult": "goog:EntitySearchResult",
    "kg": "http://g.co/kg"
  },
  "@type": "ItemList",
  "itemListElement": [
    {
      "@type": "EntitySearchResult",
      "result": {
        "@id": "kg:/m/0dl567",
        "name": "Taylor Swift",
        "@type": [
          "Thing",
          "Person"
        ],
        "description": "Singer-songwriter",
        "image": {
          "contentUrl": "https://t1.gstatic.com/images?q=tbn:ANd9GcQmVDAhjhWnN2OWys2ZMO3PGAhupp5tN2LwF_BJmiHgi19hf8Ku",
          "url": "https://en.wikipedia.org/wiki/Taylor_Swift",
          "license": "http://creativecommons.org/licenses/by-sa/2.0"
        },
        "detailedDescription": {
          "articleBody": "Taylor Alison Swift is an American singer-songwriter and actress. Raised in Wyomissing, Pennsylvania, she moved to Nashville, Tennessee, at the age of 14 to pursue a career in country music. ",
          "url": "http://en.wikipedia.org/wiki/Taylor_Swift",
          "license": "https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License"
        },
        "url": "http://taylorswift.com/"
      },
      "resultScore": 4850
    }
  ]
}

以下代码示例展示了如何使用各种支持的语言执行类似搜索。此搜索返回与 Taylor Swift 匹配的条目。

Python

"""Example of Python client calling Knowledge Graph Search API."""
import json
import urllib

api_key = open('.api_key').read()
query = 'Taylor Swift'
service_url = 'https://kgsearch.googleapis.com/v1/entities:search'
params = {
    'query': query,
    'limit': 10,
    'indent': True,
    'key': api_key,
}
url = service_url + '?' + urllib.urlencode(params)
response = json.loads(urllib.urlopen(url).read())
for element in response['itemListElement']:
  print(element['result']['name'] + ' (' + str(element['resultScore']) + ')')

Java

package com.google.knowledge.platforms.syndication.entitymatch.codesample;

import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpRequestFactory;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.jayway.jsonpath.JsonPath;
import java.io.FileInputStream;
import java.util.Properties;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

/** Example of Java client calling Knowledge Graph Search API */
public class SearchExample {
  public static Properties properties = new Properties();
  public static void main(String[] args) {
    try {
      properties.load(new FileInputStream("kgsearch.properties"));

      HttpTransport httpTransport = new NetHttpTransport();
      HttpRequestFactory requestFactory = httpTransport.createRequestFactory();
      JSONParser parser = new JSONParser();
      GenericUrl url = new GenericUrl("https://kgsearch.googleapis.com/v1/entities:search");
      url.put("query", "Taylor Swift");
      url.put("limit", "10");
      url.put("indent", "true");
      url.put("key", properties.get("API_KEY"));
      HttpRequest request = requestFactory.buildGetRequest(url);
      HttpResponse httpResponse = request.execute();
      JSONObject response = (JSONObject) parser.parse(httpResponse.parseAsString());
      JSONArray elements = (JSONArray) response.get("itemListElement");
      for (Object element : elements) {
        System.out.println(JsonPath.read(element, "$.result.name").toString());
      }
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }
}

JavaScript

<!DOCTYPE html>
<html>
<head>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
</head>
<body>
<script>
  var service_url = 'https://kgsearch.googleapis.com/v1/entities:search';
  var params = {
    'query': 'Taylor Swift',
    'limit': 10,
    'indent': true,
    'key' : '<put your api_key here>',
  };
  $.getJSON(service_url + '?callback=?', params, function(response) {
    $.each(response.itemListElement, function(i, element) {
      $('<div>', {text:element['result']['name']}).appendTo(document.body);
    });
  });
</script>
</body>
</html>

PHP

<?php
require '.api_key';
$service_url = 'https://kgsearch.googleapis.com/v1/entities:search';
$params = array(
  'query' => 'Taylor Swift',
  'limit' => 10,
  'indent' => TRUE,
  'key' => $api_key);
$url = $service_url . '?' . http_build_query($params);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = json_decode(curl_exec($ch), true);
curl_close($ch);
foreach($response['itemListElement'] as $element) {
  echo $element['result']['name'] . '<br/>';
}

知识图谱实体

知识图谱包含数百万个条目，用于描述人物、地点和事物等现实世界的实体。这些实体构成了图表的节点。

以下是知识图谱中的一些实体类型：