如何计算谷歌自然语言实体 api 响应的beginoffset

Question

我正在使用Google的自然语言analyzeEntities api，在响应中，有一个嵌套的EntityMention.TextSpan对象，有2个字段：content和beginOffset。我想利用beginOffset进行进一步的分析。所以我试图映射原始文本中的单词索引并将其与 beginOffset 进行比较，但我注意到索引不同。

我正在使用一种相当幼稚的方法来构建此索引：

const msg = "it will cost you $350 - $600,. test. Alexander. How are you?"
let index = 0
msg.split(" ").forEach(part => {
  console.log(part + ":"  + index)
  index = index + part.length + 1 // + 1 for the split on space
})

结果是：

it:0
will:3
cost:8
you:13
$350:17
-:22
$600,.:24
test.:31
Alexander.:37
How:48
are:52
you?:56

我从分析实体 api 得到的结果是：

gcloud ml language analyze-entities --content="it will cost you $350 - $600,. test. Alexander. How are you?"                
{
  "entities": [
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 23,
            "content": "test"
          },
          "type": "COMMON"
        }
      ],
      "metadata": {},
      "name": "test",
      "salience": 0.7828024,
      "type": "OTHER"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 29,
            "content": "Alexander"
          },
          "type": "PROPER"
        }
      ],
      "metadata": {},
      "name": "Alexander",
      "salience": 0.2171976,
      "type": "PERSON"
    }
  ],
  "language": "en"
}

我知道非字母数字字符具有特殊的含义和处理方式，我希望偏移量代表真正的索引。

因为，不是用于解析查询文本的规则是什么以及如何计算 beginOffset ？

谢谢！

Answer 1

您可以控制请求中的编码(用于计算偏移量(。(编码类型：https://cloud.google.com/natural-language/docs/analyzing-entities#language-entities-string-protocol(。对于python，您需要将其设置为UTF32(https://cloud.google.com/natural-language/docs/reference/rest/v1/EncodingType(。gcloud 使用 UTF-8 编码，基本上为您提供字节级偏移量。

Answer 2

看起来$符号是这里的问题。

gcloud ml language analyze-entities --content="it will cost you $350 - $600,. test. Alexander. How are you?" 
{
  "entities": [
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 31,
            "content": "test"
          },
          "type": "COMMON"
        }
      ],
      "metadata": {},
      "name": "test",
      "salience": 0.7828024,
      "type": "OTHER"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 37,
            "content": "Alexander"
          },
          "type": "PROPER"
        }
      ],
      "metadata": {},
      "name": "Alexander",
      "salience": 0.2171976,
      "type": "PERSON"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 17,
            "content": "$350"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "currency": "USD",
        "value": "350.000000"
      },
      "name": "$350",
      "salience": 0.0,
      "type": "PRICE"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 24,
            "content": "$600"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "currency": "USD",
        "value": "600.000000"
      },
      "name": "$600",
      "salience": 0.0,
      "type": "PRICE"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 18,
            "content": "350"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "value": "350"
      },
      "name": "350",
      "salience": 0.0,
      "type": "NUMBER"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 25,
            "content": "600"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "value": "600"
      },
      "name": "600",
      "salience": 0.0,
      "type": "NUMBER"
    }
  ],
  "language": "en"
}

如果您将$符号更改为#它似乎按预期工作。

gcloud ml language analyze-entities --content="it will cost you #350 - #600,. test. Alexander. How are you?" 
{
  "entities": [
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 31,
            "content": "test"
          },
          "type": "COMMON"
        }
      ],
      "metadata": {},
      "name": "test",
      "salience": 0.9085014,
      "type": "OTHER"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 37,
            "content": "Alexander"
          },
          "type": "PROPER"
        }
      ],
      "metadata": {},
      "name": "Alexander",
      "salience": 0.09149864,
      "type": "PERSON"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 18,
            "content": "350"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "value": "350"
      },
      "name": "350",
      "salience": 0.0,
      "type": "NUMBER"
    },
    {
      "mentions": [
        {
          "text": {
            "beginOffset": 25,
            "content": "600"
          },
          "type": "TYPE_UNKNOWN"
        }
      ],
      "metadata": {
        "value": "600"
      },
      "name": "600",
      "salience": 0.0,
      "type": "NUMBER"
    }
  ],
  "language": "en"
}