How to use CSS selectors to retrieve specific links lying in some class using BeautifulSoup?

问题

I am new to Python and I am learning it for scraping purposes I am using BeautifulSoup to collect links (i.e href of 'a' tag). I am trying to collect the links under the "UPCOMING EVENTS" tab of site http://allevents.in/lahore/. I am using Firebug to inspect the element and to get the CSS path but this code returns me nothing. I am looking for the fix and also some suggestions for how I can choose proper CSS selectors to retrieve desired links from any site. I wrote this piece of code:

from bs4 import BeautifulSoup

import requests

url = "http://allevents.in/lahore/"

r  = requests.get(url)

data = r.text

soup = BeautifulSoup(data)
for link in soup.select( 'html body div.non-overlay.gray-trans-back div.container div.row div.span8 div#eh-1748056798.events-horizontal div.eh-container.row ul.eh-slider li.h-item div.h-meta div.title a[href]'):
    print link.get('href')

回答1:

The page is not the most friendly in the use of classes and markup, but even so your CSS selector is too specific to be useful here.

If you want Upcoming Events, you want just the first <div class="events-horizontal">, then just grab the <div class="title"><a href="..."></div> tags, so the links on titles:

upcoming_events_div = soup.select_one('div#events-horizontal')
for link in upcoming_events_div.select('div.title a[href]'):
    print link['href']

Note that you should not use r.text; use r.content and leave decoding to Unicode to BeautifulSoup. See Encoding issue of a character in utf-8

回答2:

soup.select('div')
All elements named <div>

soup.select('#author')
The element with an id attribute of author

soup.select('.notice')
All elements that use a CSS class attribute named notice

soup.select('div span')
All elements named <span> that are within an element named <div>

soup.select('div > span')
All elements named <span> that are directly within an element named <div>, with no other element in between

soup.select('input[name]')
All elements named <input> that have a name attribute with any value

soup.select('input[type="button"]')
All elements named <input> that have an attribute named type with value button

You may also be interested by this book.

回答3:

import bs4 , requests

res = requests.get("http://allevents.in/lahore/")
soup = bs4.BeautifulSoup(res.text)
for link in soup.select('a[property="schema:url"]'):
    print link.get('href')

This code will work fine!!

来源：https://stackoverflow.com/questions/24801548/how-to-use-css-selectors-to-retrieve-specific-links-lying-in-some-class-using-be

标签

python

css

css-selectors

beautifulsoup

firebug