Classify text

Analyze text and return a list of content categories that apply to the text.

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For detailed documentation that includes this code sample, see the following:

Code sample

Go

To authenticate to Natural Language, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 


func classifyText(ctx context.Context, client *language.Client, text string) (*languagepb.ClassifyTextResponse, error) {
	return client.ClassifyText(ctx, &languagepb.ClassifyTextRequest{
		Document: &languagepb.Document{
			Source: &languagepb.Document_Content{
				Content: text,
			},
			Type: languagepb.Document_PLAIN_TEXT,
		},
		ClassificationModelOptions: &languagepb.ClassificationModelOptions{
			ModelType: &languagepb.ClassificationModelOptions_V2Model_{
				V2Model: &languagepb.ClassificationModelOptions_V2Model{
					ContentCategoriesVersion: languagepb.ClassificationModelOptions_V2Model_V2,
				},
			},
		},
	})
}

Java

To authenticate to Natural Language, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

// Instantiate the Language client com.google.cloud.language.v1.LanguageServiceClient
try (LanguageServiceClient language = LanguageServiceClient.create()) {
  // Set content to the text string
  Document doc = Document.newBuilder().setContent(text).setType(Type.PLAIN_TEXT).build();
  V2Model v2Model = V2Model.newBuilder()
      .setContentCategoriesVersion(ContentCategoriesVersion.V2)
      .build();
  ClassificationModelOptions options =
      ClassificationModelOptions.newBuilder().setV2Model(v2Model).build();
  ClassifyTextRequest request =
      ClassifyTextRequest.newBuilder()
          .setDocument(doc)
          .setClassificationModelOptions(options)
          .build();
  // Detect categories in the given text
  ClassifyTextResponse response = language.classifyText(request);

  for (ClassificationCategory category : response.getCategoriesList()) {
    System.out.printf(
        "Category name : %s, Confidence : %.3f\n",
        category.getName(), category.getConfidence());
  }
}

Node.js

To authenticate to Natural Language, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

// Imports the Google Cloud client library
const language = require('@google-cloud/language');

// Creates a client
const client = new language.LanguageServiceClient();

/**
 * TODO(developer): Uncomment the following line to run this code.
 */
// const text = 'Your text to analyze, e.g. Hello, world!';

// Prepares a document, representing the provided text
const document = {
  content: text,
  type: 'PLAIN_TEXT',
};

const classificationModelOptions = {
  v2Model: {
    contentCategoriesVersion: 'V2',
  },
};

// Classifies text in the document
const [classification] = await client.classifyText({
  document,
  classificationModelOptions,
});
console.log('Categories:');
classification.categories.forEach(category => {
  console.log(`Name: ${category.name}, Confidence: ${category.confidence}`);
});

PHP

To authenticate to Natural Language, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

use Google\Cloud\Language\V1\Document;
use Google\Cloud\Language\V1\Document\Type;
use Google\Cloud\Language\V1\LanguageServiceClient;

/**
 * @param string $text The text to analyze
 */
function classify_text(string $text): void
{
    // Make sure we have enough words (20+) to call classifyText
    if (str_word_count($text) < 20) {
        printf('20+ words are required to classify text.' . PHP_EOL);
        return;
    }
    $languageServiceClient = new LanguageServiceClient();

    // Create a new Document, add text as content and set type to PLAIN_TEXT
    $document = (new Document())
        ->setContent($text)
        ->setType(Type::PLAIN_TEXT);

    // Call the analyzeSentiment function
    $response = $languageServiceClient->classifyText($document);
    $categories = $response->getCategories();
    // Print document information
    foreach ($categories as $category) {
        printf('Category Name: %s' . PHP_EOL, $category->getName());
        printf('Confidence: %s' . PHP_EOL, $category->getConfidence());
        print(PHP_EOL);
    }
}

Python

To authenticate to Natural Language, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

from google.cloud import language_v1


def sample_classify_text(text_content):
    """
    Classifying Content in a String

    Args:
      text_content The text content to analyze.
    """

    client = language_v1.LanguageServiceClient()

    # text_content = "That actor on TV makes movies in Hollywood and also stars in a variety of popular new TV shows."

    # Available types: PLAIN_TEXT, HTML
    type_ = language_v1.Document.Type.PLAIN_TEXT

    # Optional. If not specified, the language is automatically detected.
    # For list of supported languages:
    # https://cloud.google.com/natural-language/docs/languages
    language = "en"
    document = {"content": text_content, "type_": type_, "language": language}

    content_categories_version = (
        language_v1.ClassificationModelOptions.V2Model.ContentCategoriesVersion.V2
    )
    response = client.classify_text(
        request={
            "document": document,
            "classification_model_options": {
                "v2_model": {"content_categories_version": content_categories_version}
            },
        }
    )
    # Loop through classified categories returned from the API
    for category in response.categories:
        # Get the name of the category representing the document.
        # See the predefined taxonomy of categories:
        # https://cloud.google.com/natural-language/docs/categories
        print(f"Category name: {category.name}")
        # Get the confidence. Number representing how certain the classifier
        # is that this category represents the provided text.
        print(f"Confidence: {category.confidence}")

What's next

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