telegram bot example uses the tesseract to process OCR request

ocr_bot.py

import sys
import asyncio
import random
import telepot
from telepot.delegate import per_chat_id
from telepot.async.delegate import create_open

import os
import traceback

try:
    import Image
except ImportError:
    from PIL import Image
import pytesseract

class OCRBot(telepot.helper.ChatHandler):
    def __init__(self, seed_tuple, timeout):
        super(OCRBot, self).__init__(seed_tuple, timeout)
        self._lang = 'eng'

    @asyncio.coroutine
    def on_message(self, msg):
        content_type, chat_type, chat_id = telepot.glance2(msg)

        if content_type == 'photo':
            photo_id = msg['photo'][-1:][0]['file_id']
            width = msg['photo'][-1:][0]['width']
            height = msg['photo'][-1:][0]['height']
            to_save = './downloads/' + photo_id
            yield from self.sender.sendMessage('Trying to download the file({}*{}) you sent...'.format(width, height))
            yield from bot.downloadFile(photo_id, to_save)
            yield from self.sender.sendMessage('Download complete. Start OCR...')
            try:
                text = pytesseract.image_to_string(Image.open(to_save), lang=self._lang)
            except:
                yield from self.sender.sendMessage('Failed to process OCR')
                traceback.print_exc()
                os.remove(to_save)
                return;

            os.remove(to_save)
            yield from self.sender.sendMessage('Done. Removed the temp file. Here is the result:')
            yield from self.sender.sendMessage(text)
            return

        elif content_type == 'text':
            commands = msg['text'].strip().lower().split()

            if commands[0] == '/getlang' or commands[0] == 'getlang':
                yield from self.sender.sendMessage(self._lang)
                return;
            if commands[0] == '/setlang' or commands[0] == 'setlang':
                self._lang = commands[1]
                yield from self.sender.sendMessage('current lang setting: %s' % self._lang )
            if commands[0] == '/?' or commands[0] == '?':
                show_keyboard = {'keyboard': [['getlang', 'setlang kor','setlang eng', 'hidekbd']]}
                yield from self.sender.sendMessage('Get help!', reply_markup=show_keyboard)
            elif commands[0] == '/hidekbd' or commands[0] == 'hidekbd':
                hide_keyboard = {'hide_keyboard': True}
                yield from self.sender.sendMessage('Hide helps', reply_markup=hide_keyboard)


TOKEN = '**YOUR TOKEN**'

bot = telepot.async.DelegatorBot(TOKEN, [
    (per_chat_id(), create_open(OCRBot, timeout=60)),
])
loop = asyncio.get_event_loop()

loop.create_task(bot.messageLoop())
print('Listening ...')

loop.run_forever()