Text Translator: Translating Text Messages using Google Translate API & Twilio
Every time I have dinner or spend time with my in-laws, I'm always wishing that I was able to understand Korean -- I dream of a day when I can get subtitles while they are talking. Alas, we only see them a few times of the year, but the subtitles got me thinking about how can I communicate with them more regularly? So I wrote a script that my in-laws can text a phone number in Korean and my app will translate it and send me the message in English!
Whenever I text that number in English, it'll translate my message into Korean and send it to either my mother-in-law or father-in-law.
I'm using Webapp2 as my web framework and I made a route to handle Twilio text messages (don't know how to use Twilio? Check out Twilio 2 Ways of Sending Text Messages). I started this project by creating a Request Handler that accepts only POST request because that is what Twilio web hooks provide and accept.[code language="python"]class ProcessText(webapp2.RequestHandler):"""A POST Request Handler"""def post(self):"""Receives a POST request"""from_phone_number = self.request.get("From")[1:]message = self.request.get("Body").lower()to_phone_number, response = process_message(from_phone_number, message)send_text_message(to_phone_number, response)[/code]On lines 7 & 8, I am getting the data from Twilio's post request and setting them to from_phone_number and message. I am not getting the first index of the phone number because that would include a "+" which I do not need. Then on line 10, I process the message and get back the phone number in which this app should send the text message to and what the message is after the translation. Finally, I called the send_text_message function giving it the to_phone_number and the translated message so Twilio can send it. Let's process the message![code language="python"]def process_message(from_phone_number, message):"""Processes message, returns from who and translated message"""to_phone_number = MY_PHONE_NUMBERif from_phone_number == MY_PHONE_NUMBER:to_who = message[:3]to_phone_number = PARENTS[to_who]message = message[3:][/code]I bring in my actual phone number and set that to the to_phone_number.If the from_phone_number is from me, I need to pull off the first 3 characters from my message and use that to rebind to_phone_number to either mom or dad's number (by using the PARENTS dictionary) and rebind message to be without the 3 first characters. At this point I now know who the message is for and I have the correct message to actually process:[code language="python"]translated_message = translation(to_phone_number, message)[/code]I call the translation function:[code language="python"]def translation(to_phone_number, message):"""Makes an API call to translate the message."""translation = translate_client.translate(message,target_language=PHONE_DIRECTORY[to_phone_number]['language'])return translation[u'translatedText'].encode('utf-8')[/code]The translate_client is an instance of Google Translate and I pass my message and the targeted language by using my PHONE_DIRECTORy using the phone number as a key and getting that person's preferred language (ie. My mother-in-law's phone will give 'ko' for Korean and my phone number will give 'en' for English). I return the actual translations and since Python 2.7 doesn't support Korean characters, I need to use .encode('uft-8') so python can process these special characters.Then I return to my process_message function, where I check to see if the original text was sent from my in-laws again.[code language="python"]if from_phone_number != MY_PHONE_NUMBER:translated_message = "{}: {}".format(FROM_PARENTS[from_phone_number].upper(), translated_message.encode('utf-8'))return (to_phone_number, translated_message)[/code]I do this because I am using the same Twilio phone number for both parents, and I need to know who actually sent me the text when I receive it on my phone -- I add either "MOM:" or "DAD:" to the message.Now I can return the to_phone_number and my translated_message to the original post function where the send_text_message function gets called.[code language="python"]def send_text_message(phone, message):"""sends a text message to the phone number""""try:twilio_client = TwilioRestClient(TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN)message = twilio_client.messages.create(body=message,to="+"+phone,from_ = TWILIO_NUMBER)except twilio.TwilioRestException as e:print e[/code]In this function I do a try/except so I can handle any errors from Twilio. On line 5, I create a Twilio instance and then I create a message, passing in my translated message and to_phone_number. Then tada! It sends the text!In order to make this work you'll need a Twilio account (guide) and Google Translate API account (docs) as well as a config.py file where you source your actual phone numbers for the terminal environment and set up the relationships (who to send it to and in what language). Since I am using one phone number for two people, its a little complicated, but if you are only using this for a one-to-one relationship it'll be simpler.
Check out the full code here
Finally, to actually get it working in development, I used Google App Engine to deploy and that's why there is app.yaml and appengine_config.py files. Checkout Google App Engine docs to learn how to deploy your web application.