如何从多个 `<a href="" title=""> 标签中提取所有的 href 和标题？

Question

鉴于此file：

<a data-parent="#accordion1" data-toggle="collapse" href="# fruitName1" title="Click to expand drug name">
<span class="list-unstyled" style="text-decoration: none;"></span> GLIPIZIDE 
         </a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114223" title="Click to view LEMONS (LEMONS) | POQ  #114223 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 1 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114226" title="Click to view LEMONS (LEMONS) | POQ  #114226 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 2 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114305" title="Click to view LEMONS (LEMONS) | POQ  #114305 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 3 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114370" title="Click to view LEMONS (LEMONS) | POQ  #114370 | BOX;67 PZ | Discontinued | FRUIT COMPANY 1 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114378" title="Click to view LEMONS (LEMONS) | POQ  #114378 | BOX;67 PZ | Discontinued | FRUIT COMPANY 4 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114387" title="Click to view LEMONS (LEMONS) | POQ  #114387 | BOX;67 PZ | Discontinued | FRUIT COMPANY 5 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114438" title="Click to view LEMONS (LEMONS) | POQ  #114438 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 2 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114497" title="Click to view LEMONS (LEMONS) | POQ  #114497 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 5 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114542" title="Click to view LEMONS (LEMONS) | POQ  #114542 | BOX;67 PZ | Discontinued | FRUIT COMPANY 3 ">
                              LEMONS (LEMONS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=114550" title="Click to view LEMONS (LEMONS) | POQ  #114550 | 
         </a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=117270" title="Click to view GRAPES (GREEN GRAPES ; AUS) | POQ  #117270 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 10  ">
                              GRAPES (GREEN GRAPES ; AUS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=117511" title="Click to view GRAPES (GREEN GRAPES ; AUS) | POQ  #117511 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 11 ">
                              GRAPES (GREEN GRAPES ; AUS)</a>
<a href="/loads/data/usersindex.cfm?event=overview.subprocess&amp;ApplNo=117620" title="Click to view GRAPES (GREEN GRAPES ; AUS) | POQ  #117620 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 12 ">

使用正则表达式或漂亮的汤，如何提取所有<a href="" title="">，在href标签前添加www.example.com：

www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=114223 |  title= | Click to view LEMONS (LEMONS) | POQ  #114223 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 1 | LEMONS (LEMONS)
www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=114226 |  title= | Click to view LEMONS (LEMONS) | POQ  #114226 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 2 | LEMONS (LEMONS)
www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=114305 |  title= | Click to view LEMONS (LEMONS) | POQ  #114305 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 3 | LEMONS (LEMONS)
www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=114370 |  title= | Click to view LEMONS (LEMONS) | POQ  #114370 | BOX;67 PZ | Discontinued | FRUIT COMPANY 1 | LEMONS (LEMONS)

我尝试过：

for a in soup.tbody.findAll('a', href=True):
    r = re.compile('(?<=href=").*?(?=")')
    r.findall(str(a)

还有：

for a in soup.tbody.findAll('a', href=True):
    print (a.find('a')['href'])
    print (a.find('a')['title'])

但是，我不知道如何重新排列标题和 href。 更新

根据 odradek 的回答，我尝试了这个：

soup = BeautifulSoup(open('file.htm'), 'lxml')
for a in soup.tbody.findAll('a', href=True):
    html = a
    PREFIX = 'www.example.com'
    template = '{prefix}{url} | {title}'.format
    links = [template(prefix=PREFIX, url=e['href'], title=e['title']) for e in html.find_all('a', href=True)]
    print(links)

但是我得到了：

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Answer 1

您可以使用 BeautifulSoup 解析方法而不是复杂的正则表达式：

# this is the url you want to add at the beginning
PREFIX = 'www.example.com'

# the template of your desired output
template = '{prefix}{url} | {title}'.format

# the resulting list, please note that "html" variable is
# the given source code.
links = [template(prefix=PREFIX, url=e.get('href'), title=e.get('title'))
         for e in html.find_all('a', href=True)]

当遇到您列表中的两个 a 标记时：

$ python get_all_a.py
www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=117511 | Click to view GRAPES (GREEN GRAPES ; AUS) | POQ  #117511 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 11 
www.example.com/loads/data/usersindex.cfm?event=overview.subprocess&ApplNo=117620 | Click to view GRAPES (GREEN GRAPES ; AUS) | POQ  #117620 | BOX;67 PZ | PRESENTATION | FRUIT COMPANY 12 

根据您的更新，您不应该将这段代码放在 for 循环中，而是：

html = BeautifulSoup(open('file.htm'), 'html.parser')

PREFIX = 'www.example.com'

template = '{prefix}{url} | {title}'.format

# inside this list comprehension is your for loop implied
links = [template(prefix=PREFIX, url=e.get('href'), title=e.get('title'))
         for e in html.find_all('a', href=True)]

Answer 2

这不是正则表达式的任务。您可以使用 odradek 的回答中介绍的 BeautifulSoup，或者我最喜欢的替代方案 lxml，在我看来，这会导致代码更具可读性：

from lxml import etree

tree = etree.fromstring(html)
for element in tree.xpath('//a'):
    print('www.example.com' + element.get('href'))
    print('title: ' + element.get('title'))