Introduction to Flask

Workshop given for a Swisscom Digital Lab meetup at EPFL

Transcript

1. Introduction to Flask Sébastien Fievet Swisscom Digital Lab at EPFL
2. Prerequisites
3. $ python --version Python 2.7.12 https://www.python.org/downloads
4. $ pip --version pip 9.0.1 https://pip.pypa.io/en/stable/installing/
5. $ pip install virtualenv $ virtualenv --version 13.1.2 https://virtualenv.pypa.io/en/stable/installation/
6. $ git clone \ https://github.com/zyegfryed/intro_to_flask.git $ cd intro_to_flask $ virtualenv .venv $ source .venv/bin/activate
7. Hello Flask!
8. –Deny “What… Why Flask?”
9. –http://flask.pocoo.org/ “Flask is a microframework for Python based on Werkzeug, Jinja 2 and good intentions.”
10. Diving In https://github.com/zyegfryed/intro_to_flask/tree/01_intro
11. $ pip install Flask http://flask.pocoo.org/docs/0.12/installation/
12. # app.y from flask import Flask app = Flask(__name__) @app.route('/') def hello_world(): return 'Hello, World!'
13. $ git checkout 01_intro $ export FLASK_APP=app.py $ flask run $ curl http://127.0.0.1:5000/ Hello, World!
14. Chatbot
15. Diving In https://github.com/zyegfryed/intro_to_flask/tree/02_chatbot
16. $ pip install fbmessenger https://github.com/rehabstudio/fbmessenger
17. # app.py @app.route('/webhook', methods=['GET', 'POST']) def webhook(): if request.method == 'GET': if request.args.get('hub.verify_token') == \ os.environ.get('FB_VERIFY_TOKEN'): return request.args.get('hub.challenge') raise ValueError('FB_VERIFY_TOKEN does not match.')
18. # app.py @app.route('/webhook', methods=['GET', 'POST']) def webhook(): […] elif request.method == 'POST': messenger.handle(request.get_json(force=True)) return ''
19. # app.py from fbmessenger import BaseMessenger from fbmessenger import elements class Messenger(BaseMessenger): def message(self, message): element = elements.Text('Received: {0}’.format( message['message']['text'])) self.send(element.to_dict()) […]
20. # app.py messenger = \ Messenger(os.environ.get(‘FB_PAGE_TOKEN’))
21. $ ngrok --version ngrok version 2.1.18 https://ngrok.com/download
22. Messenger https://developers.facebook.com/docs/messenger- platform/guides/setup
23. $ git checkout 02_chatbot $ export FB_VERIFY_TOKEN=… $ export FB_PAGE_TOKEN=… $ flask run - - - - - - - - - — - - - - - - - - - - - - $ ngrok http 5000
24. Async
25. Diving In https://github.com/zyegfryed/intro_to_flask/tree/03_async
26. # app.py from redis import StrictRedis redis = StrictRedis() @job('default', connection=redis) def messenger_handle(message): messenger.handle(message) @app.route('/webhook', methods=['GET', 'POST']) def webhook(): […] elif request.method == 'POST': messenger_handle.delay(request.get_json(force=True)) return ''
27. $ redis-server --version Redis server v=3.2.8 https://redis.io/download
28. $ pip install rq http://python-rq.org/
29. $ git checkout 03_async $ export FB_PAGE_TOKEN=… $ rqworker default - - - - - - - - - — - - - - - - - - - - - - $ redis-server
30. Links • https://github.com/zyegfryed/intro_to_flask • https://www.python.org/downloads/ • https://pip.pypa.io/en/stable/installing/ • http://flask.pocoo.org/ • http://flask.pocoo.org/docs/0.12/quickstart/ • https://developers.facebook.com/docs/messenger-platform/guides/setup • https://github.com/rehabstudio/fbmessenger • https://redis.io/download • http://python-rq.org/ • https://github.com/rehabstudio/fbmessenger