Quickstart: Use the Translator Text API to detect text language using Python

In this quickstart, you'll learn how to detect the language of provided text using Python and the Translator Text REST API.

This quickstart requires an Azure Cognitive Services account with a Translator Text resource. If you don't have an account, you can use the free trial to get a subscription key.


This quickstart requires:

  • Python 2.7.x or 3.x
  • An Azure subscription key for Translator Text

Create a project and import required modules

Create a new Python project using your favorite IDE or editor. Then copy this code snippet into your project in a file named detect.py.

# -*- coding: utf-8 -*-
import os, requests, uuid, json


If you haven't used these modules you'll need to install them before running your program. To install these packages, run: pip install requests uuid.

The first comment tells your Python interpreter to use UTF-8 encoding. Then required modules are imported to read your subscription key from an environment variable, construct the http request, create a unique identifier, and handle the JSON response returned by the Translator Text API.

Set the subscription key, base url, and path

This sample will try to read your Translator Text subscription key from the environment variable TRANSLATOR_TEXT_KEY. If you're not familiar with environment variables, you can set subscriptionKey as a string and comment out the conditional statement.

Copy this code into your project:

# Checks to see if the Translator Text subscription key is available
# as an environment variable. If you are setting your subscription key as a
# string, then comment these lines out.
if 'TRANSLATOR_TEXT_KEY' in os.environ:
    subscriptionKey = os.environ['TRANSLATOR_TEXT_KEY']
    print('Environment variable for TRANSLATOR_TEXT_KEY is not set.')
# If you want to set your subscription key as a string, uncomment the line
# below and add your subscription key.
#subscriptionKey = 'put_your_key_here'

The Translator Text global endpoint is set as the base_url. path sets the detect route and identifies that we want to hit version 3 of the API.


For more information about endpoints, routes, and request parameters, see Translator Text API 3.0: Detect.

base_url = 'https://api.cognitive.microsofttranslator.com'
path = '/detect?api-version=3.0'
constructed_url = base_url + path

Add headers

The easiest way to authenticate a request is to pass in your subscription key as an Ocp-Apim-Subscription-Key header, which is what we use in this sample. As an alternative, you can exchange your subscription key for an access token, and pass the access token along as an Authorization header to validate your request. For more information, see Authentication.

Copy this code snippet into your project:

headers = {
    'Ocp-Apim-Subscription-Key': subscriptionKey,
    'Content-type': 'application/json',
    'X-ClientTraceId': str(uuid.uuid4())

Create a request to detect text language

Define the string (or strings) that you want to detect the language for:

# You can pass more than one object in body.
body = [{
    'text': 'Salve, mondo!'

Next, we'll create a POST request using the requests module. It takes three arguments: the concatenated URL, the request headers, and the request body:

request = requests.post(constructed_url, headers=headers, json=body)
response = request.json()

The last step is to print the results. This code snippet prettifies the results by sorting the keys, setting indentation, and declaring item and key separators.

print(json.dumps(response, sort_keys=True, indent=4, ensure_ascii=False, separators=(',', ': ')))

Put it all together

That's it, you've put together a simple program that will call the Translator Text API and return a JSON response. Now it's time to run your program:

python detect.py

If you'd like to compare your code against ours, the complete sample is available on GitHub.

Sample response

Find the country/region abbreviation in this list of languages.

        "alternatives": [
                "isTranslationSupported": true,
                "isTransliterationSupported": false,
                "language": "pt",
                "score": 1.0
                "isTranslationSupported": true,
                "isTransliterationSupported": false,
                "language": "en",
                "score": 1.0
        "isTranslationSupported": true,
        "isTransliterationSupported": false,
        "language": "it",
        "score": 1.0

Clean up resources

If you've hardcoded your subscription key into your program, make sure to remove the subscription key when you're finished with this quickstart.

Next steps

See also

Learn how to use the Translator Text API to: