Webscraping mit Python

Importing Data in Python (Fortgeschritten)

Hugo Bowne-Anderson

Data Scientist at DataCamp

HTML

Mix aus unstrukturierten und strukturierten Daten
Strukturierte Daten:
- Vordefiniertes Datenmodell oder
- Auf eine bestimmte Art organisiert
Unstrukturierte Daten: keine dieser Eigenschaften

ch_1_3.008.png

BeautifulSoup

Strukturierte Daten aus HTML analysieren und extrahieren

ch_1_3.011.png

Extrahiert schöne Infos aus einer Tag-Suppe

BeautifulSoup

from bs4 import BeautifulSoup
import requests
url = 'https://www.crummy.com/software/BeautifulSoup/'
r = requests.get(url)
html_doc = r.text
soup = BeautifulSoup(html_doc)

soup.prettify()

print(soup.prettify())

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/transitional.dtd">
<html>
 <head>
  <meta content="text/html; charset=utf-8" http-equiv="Content-Type"/>
  <title>
   Beautiful Soup: We called him Tortoise because he taught us.
  </title>
  <link href="mailto:[email protected]" rev="made"/>
  <link href="/nb/themes/Default/nb.css" rel="stylesheet" type="text/css"/>
  <meta content="Beautiful Soup: a library designed for screen-scraping HTML and XML." name="Description"/>
  <meta content="Markov Approximation 1.4 (module: leonardr)" name="generator"/>
  <meta content="Leonard Richardson" name="author"/>
 </head>
 <body alink="red" bgcolor="white" link="blue" text="black" vlink="660066">
  <img align="right" src="10.1.jpg" width="250"/>
  <br/>
  <p>

BeautifulSoup erkunden

Viele Methoden wie zum Beispiel:

print(soup.title)

<title>Beautiful Soup: We called him Tortoise because he taught us.</title>

print(soup.get_text())

Beautiful Soup: We called him Tortoise because he taught us.
You didn't write that awful page. You're just trying to
get some data out of it. Beautiful Soup is here to 
help. Since 2004, it's been saving programmers hours or
days of work on quick-turnaround screen scraping 
projects.

BeautifulSoup erkunden

find_all()

for link in soup.find_all('a'):
    print(link.get('href'))

bs4/download/
#Download
bs4/doc/
#HallOfFame
https://code.launchpad.net/beautifulsoup
https://groups.google.com/forum/?fromgroups#!forum/beautifulsoup
http://www.candlemarkandgleam.com/shop/constellation-games/
http://constellation.crummy.com/Constellation%20Games%20excerpt.html
https://groups.google.com/forum/?fromgroups#!forum/beautifulsoup
https://bugs.launchpad.net/beautifulsoup/
http://lxml.de/
http://code.google.com/p/html5lib/

Lass uns üben!

Importing Data in Python (Fortgeschritten)