Python para desarrolladores web

http://creativecommons.org/licenses/by-nc-sa/3.0/

Leganés, 11 y 12 de

febrero

José Manuel Ortega

Leganés, 11 y 12 de febrero

José Manuel Ortega

@jmortegac

Python para desarrolladores web






2 Python para desarrolladores web

https://speakerdeck.com/jmortega

https://speakerdeck.com/jmortega

Stack,Django,Flask,Pyramid

Requests

Scraping(BeautifulSoap,Scrapy)

Bokeh

API Rest (Django-Rest-Framework)

Twitter API


Agenda


Python Zen

Stack


Django


Django

7

Most popular Python web framework

Full stack web framework Django-ORM

Template Engine

HTTP Request/Response

URL Routing Mechanism

Testing

Dev Server (WSGI)


Django

8

Model Template View Model → modelo de datos (models.py)

View →vistas de datos (views.py): qué datos se presentan

Template → plantillas HTML:cómo se presentan los datos


Django

9

django.contrib.auth Un sistema de autenticación

django.contrib.contenttypes Un framework para

tipos de contenidos

django.contrib.sessions Un framework para

manejar sesiones

DATABASES = {

'default': {

'ENGINE': 'django.db.backends.sqlite3',

'NAME': 'mysite.db',

}

}


Django ORM


Django Templates

11

Templates are composed by Blocks


Django example project


Django example project


Django-oscar

14

http://oscarcommerce.com

https://github.com/django-oscar/django-oscar


http://oscarcommerce.com/






Flask

15

Microframework

Built in development server and debugger

Oriented to small applications with simpler

requirements.


Flask example


Flask


Flask


http://httpbin.org

http://httpbin.org/

Pyramid

19

Python3 compatible

Templates with Chamaleon

Like django has his own bootstraping

toolpcreate


Pyramid

20

pcreate -s starter hello_pyramid

├── CHANGES.txt

├── development.ini

├── MANIFEST.in

├── production.ini

├── hello_pyramid

│ ├── __init__.py

│ ├── static

│ │ ├── pyramid-16x16.png

│ │ ├── pyramid.png

│ │ ├── theme.css

│ │ └── theme.min.css

│ ├── templates

│ │ └── mytemplate.pt

│ ├── tests.py

│ └── views.py

├── README.txt

└── setup.py


Pyramid

Learn REST API with Python in 90 minutes 21

Pyramid


Pserve development.ini

Pyramid

23

https://badges.fedoraproject.org

https://github.com/fedora-infra/tahrir


https://badges.fedoraproject.org/




Comparing web frameworks

24

Django Pyramid Flask

ORM Django-

ORM

Bootstrapping django-

admin

pcreate

Templates Chameleon

Migrations

Admin

interface

Visual debug


Requests Module

Python’s standard urllib2,httplib module provides most

of the HTTP capabilities you need, but the API is

thoroughly broken.

Python HTTP: Requests. Beautiful, simple, Pythonic.

25

http://www.python-requests.org


http://www.python-requests.org/



Use requests module

Install requests module (pip install requests) http://docs.python-requests.org/en/latest/user/install/#install

Use it interactive mode $ python

>>> import requests

>>> r = requests.get("http://httpbin.org/get")


http://docs.python-requests.org/en/latest/user/install/#install



Use requests module


Use requests module


Beautiful Soup

29

Librería que permite el parseo de páginas web

Soporta parsers como lxml,html5lib

Instalación

pip install lxml

pip instlal html5lib

pip install beautifulsoup4


Obtain links with bs4


Obtain links with bs4


Extract images with lxml

32

import requests

from lxml import html


Extract program


JSON in python

34

import json

json_dumps(data, sort_keys=True)

Maybe allow human readable output

json_dumps(data, sort_keys=True, indent=4)


Scrapy


Scrapy / pip install scrapy


Scrapy shell

37

scrapy shell <url>

from scrapy. import Selector

hxs = Selector(response)

Info = hxs.select(‘//div[@class=“slot-inner”]’)


Scrapy shell


Scrapy spiders


Scrapy spiders

40

$ scrapy crawl <spider_name> $ scrapy crawl <spider_name> -o items.json -t json

$ scrapy crawl <spider_name> -o items.csv -t csv

$ scrapy crawl <spider_name> -o items.xml -t xml


Twisted

41

Event-driven networking engine

Procesar eventos de forma asíncrona

https://twistedmatrix.com


https://twistedmatrix.com/

Bokeh

42

Interactive, browser-based visualization for big

data, driven from Python

http://bokeh.pydata.org

Rich interactivity over large datasets

HTML5 Canvas

Integration with Google Maps

http://bokeh.pydata.org/en/latest/docs/gallery.html


http://bokeh.pydata.org/

http://bokeh.pydata.org/en/latest/docs/gallery.html

Bokeh


Bokeh Google maps


Bokeh Google maps


Javascript code generation


Bokeh charts


API Rest in Python

48

Django Rest Framework (DRF)

pip install djangorestframework


Django Rest Framework

49

Serializers & Views


class PostSerializer(serializers.HyperlinkedModelSerializer):

class Meta:

model = Post

fields = ('author', 'title', 'text', 'created_date','published_date')

class PostViewSet(viewsets.ModelViewSet):

queryset = Post.objects.all()

serializer_class = PostSerializer

from rest_framework import routers, serializers, viewsets


50

Urls




Twitter API

52

https://apps.twitter.com

Oauth2

Consumer API (API KEY)

Consumer Secret (API Secret)

Access Token

Access Token Secret


https://apps.twitter.com/

Twitter API

53

Python-twitter

https://github.com/bear/python-twitter

Tweepy

https://github.com/tweepy/tweepy





https://github.com/tweepy/tweepy

Tweepy

54

import tweepy

from tweepy import OAuthHandler

consumer_key = 'YOUR-CONSUMER-KEY'

consumer_secret = 'YOUR-CONSUMER-SECRET'

access_token = 'YOUR-ACCESS-TOKEN'

access_secret = 'YOUR-ACCESS-SECRET'

auth = OAuthHandler(consumer_key, consumer_secret)

auth.set_access_token(access_token, access_secret)

api = tweepy.API(auth)


Tweepy


Timeline

Tweet list

Trending topic

for status in tweepy.Cursor(api.home_timeline).items(10):

print(status.text)

for tweet in tweepy.Cursor(api.user_timeline).items():

process_or_store(tweet._json)

def getTrends():

trends = api.trends_place(1)[0]['trends']

return trends

Python-twitter

56

import twitter

apiTwitter = twitter.Api(consumer_key="xxx", consumer_secret="xxx",

access_token_key="xxx", access_token_secret="xxx")

query = apiTwitter.GetSearch("#T3chFest2016“,count=50)

for result in query:

tweet = {}

tweet['text'] = result.text.encode('utf-8')

tweet['date'] = result.created_at.encode('utf-8')

tweet['favorite_count'] = result.favorite_count

tweet['lang'] = result.lang.encode('utf-8')

tweet['retweet_count'] = result.retweet_count

tweet['account'] = result.user.screen_name.encode('utf-8')

twitter_results.append(tweet)



Python-twitter

Python-twitter

58

outfile = open('twitter.json','wb')

for twitter_result in twitter_results:

line = json.dumps(twitter_result) + "\n"

outfile.write(line)


Python in the cloud


Python in the cloud


Python in the cloud


Git

https://github.com/jmortega/t3chfest_python_examples


https://github.com/jmortega/t3chfest_python_examples

References

Django project: http://www.djangoproject.com

Flask: http://flask.pocoo.org

Pyramid: http://www.pylonsproject.org

Requests python module: http://www.python-requests.org

BeautifulSoup: http://www.crummy.com/software/BeautifulSoup

Bokeh:http://bokeh.pydata.org

Django Rest:http://www.django-rest-framework.org

https://www.pythonanywhere.com


http://www.djangoproject.com/

http://flask.pocoo.org/

http://www.pylonsproject.org/




http://www.crummy.com/software/BeautifulSoup

http://bokeh.pydata.org/

http://www.django-rest-framework.org/





https://www.pythonanywhere.com/

Thank you! José Manuel Ortega <@jmortegac>

Software

Python para desarrolladores web