使用python从网站上抓取每个产品的href

Question

我正在使用 beautifulsoup 来抓取此网页中每个产品的 href：http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=digital+camera。这些 href 以“keywords=digital+camera”结尾 这是我的代码：

from bs4 import BeautifulSoup
import requests

url = "http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=digital+camera"
keyword = "keywords=digital+camera"
r = requests.get(url)
data = r.text
soup = BeautifulSoup(data)
for link in soup.find_all('a'):
    href = link.get('href')
    if href is None:
        continue
    elif keyword in href:  
        print href

我没有从上面的脚本中得到任何反馈，有什么可以解决的吗？ 谢谢

Answer 1

亚马逊正在检测用户代理（“您的浏览器名称”）并根据该值更改内容。如果您将用户代理添加到请求中，您将获得添加了“keyword=digital+camera”的字符串。否则，你不会。

url ="http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=digital+camera"
import urllib2
from bs4 import BeautifulSoup
req = urllib2.Request(url, headers={ 'User-Agent': 'Mozilla/5.0' })
html = urllib2.urlopen(req).read()
soup = BeautifulSoup(html)
links = soup.find_all('a')
for l in links:
    href = l.get('href')
    title = l.get('title', '')
    if 'Sony W800/B 20.1 MP Digital' in title:
        print(href)  # prints: http://www.amazon.com/Sony-W800-Digital-Camera-Black/dp/B00I8BIBCW/ref=sr_1_2/183-0842534-8993425?s=photo&ie=UTF8&qid=1421400650&sr=1-2&keywords=digital+camera