在 Beautiful Soup 中抓取多个页面进行解析

Question

我正在尝试从单个网站上抓取多个页面以供 BeautifulSoup 解析。到目前为止，我已经尝试使用 urllib2 来执行此操作，但遇到了一些问题。我尝试过的是：

import urllib2,sys
from BeautifulSoup import BeautifulSoup

for numb in ('85753', '87433'):
    address = ('http://www.presidency.ucsb.edu/ws/index.php?pid=' + numb)
html = urllib2.urlopen(address).read()
soup = BeautifulSoup(html)

title = soup.find("span", {"class":"paperstitle"})
date = soup.find("span", {"class":"docdate"})
span = soup.find("span", {"class":"displaytext"})  # span.string gives you the first bit
paras = [x for x in span.findAllNext("p")]

first = title.string
second = date.string
start = span.string
middle = "\n\n".join(["".join(x.findAll(text=True)) for x in paras[:-1]])
last = paras[-1].contents[0]

print "%s\n\n%s\n\n%s\n\n%s\n\n%s" % (first, second, start, middle, last)

这只给出了 numb 序列中第二个数字的结果，即 http://www.presidency.ucsb.edu/ws/index.php?pid=87433。我也尝试过使用mechanize，但没有成功。理想情况下，我希望能够做的是拥有一个带有链接列表的页面，然后自动选择一个链接，将 HTML 传递给 BeautifulSoup，然后移至列表中的下一个链接。

Answer 1

您需要将其余代码放入循环内。现在，您正在迭代元组中的两个项目，但在迭代结束时，只有最后一个项目仍分配给 address ，随后在循环外对其进行解析。

Answer 2

我认为您只是错过了循环中的缩进：

import urllib2,sys
from BeautifulSoup import BeautifulSoup

for numb in ('85753', '87433'):
    address = ('http://www.presidency.ucsb.edu/ws/index.php?pid=' + numb)
    html = urllib2.urlopen(address).read()
    soup = BeautifulSoup(html)

    title = soup.find("span", {"class":"paperstitle"})
    date = soup.find("span", {"class":"docdate"})
    span = soup.find("span", {"class":"displaytext"})  # span.string gives you the first bit
    paras = [x for x in span.findAllNext("p")]

    first = title.string
    second = date.string
    start = span.string
    middle = "\n\n".join(["".join(x.findAll(text=True)) for x in paras[:-1]])
    last = paras[-1].contents[0]

    print "%s\n\n%s\n\n%s\n\n%s\n\n%s" % (first, second, start, middle, last)

我认为这应该可以解决问题..

Answer 3

这是一个更简洁的解决方案（使用 lxml）：

import lxml.html as lh

root_url = 'http://www.presidency.ucsb.edu/ws/index.php?pid='
page_ids = ['85753', '87433']

def scrape_page(page_id):
    url = root_url + page_id
    tree = lh.parse(url)

    title = tree.xpath("//span[@class='paperstitle']")[0].text
    date = tree.xpath("//span[@class='docdate']")[0].text
    text = tree.xpath("//span[@class='displaytext']")[0].text_content()

    return title, date, text

if __name__ == '__main__':
    for page_id in page_ids:
        title, date, text = scrape_page(page_id)