我使用这段代码获取一些带有BeautifulSoup的html表行:
from bs4 import BeautifulSoup
import urllib2
import re
page = urllib2.urlopen('www.something.bla')
soup = BeautifulSoup(page)
rows = soup.findAll('tr', attrs={'class': re.compile('class1.*')})
这就是我得到的结果:
<tr class="class1 class2 class3">...</tr>
<tr class="class1 class2 class3">...</tr>
<tr class="class1 class5">...</tr>
<tr class="class1_a class5_a">...</tr>
<tr class="class1 class5">...</tr>
<tr class="class1_a class5_a">...</tr>
<!-- etc. -->
但是,我想排除(或者不首先选择它们)那些以class1 class2 class3
作为属性的行。
我该怎么办?
谢谢你的帮助!
答案 0 :(得分:9)
如果没有正则表达式,也许更容易。这适用于BeautifulSoup 3:
from BeautifulSoup import BeautifulSoup
page = """
<tr class="class1 class2 class3">1</tr>
<tr class="class1 class2 class3">2</tr>
<tr class="class1 class5">3</tr>
<tr class="class1_a class5_a">4</tr>
<tr class="class1 class5">5</tr>
<tr class="class1_a class5_a">6</tr>
<tr>7</tr>"""
def cond(x):
if x:
return x.startswith("class1") and not "class2 class3" in x
else:
return False
soup = BeautifulSoup(page)
rows = soup.findAll('tr', {'class': cond})
for row in rows:
print row
=&GT;
<tr class="class1 class5">3</tr>
<tr class="class1_a class5_a">4</tr>
<tr class="class1 class5">5</tr>
<tr class="class1_a class5_a">6</tr>
使用BeautifulSoup 4,我能够使其工作如下:
import re
from bs4 import BeautifulSoup
page = """
<tr class="class1 class2 class3">1</tr>
<tr class="class1 class2 class3">2</tr>
<tr class="class1 class5">3</tr>
<tr class="class1_a class5_a">4</tr>
<tr class="class1 class5">5</tr>
<tr class="class1_a class5_a">6</tr>
<tr>7</tr>"""
soup = BeautifulSoup(page)
rows = soup.find_all('tr', {'class': re.compile('class1.*')})
for row in rows:
cls = row.attrs.get("class")
if not ("class2" in cls or "class3" in cls):
print row
=&GT;
<tr class="class1 class5">3</tr>
<tr class="class1_a class5_a">4</tr>
<tr class="class1 class5">5</tr>
<tr class="class1_a class5_a">6</tr>
在BS4中,像class
这样的多值属性将字符串列表作为其值,而不是字符串。请参阅http://www.crummy.com/software/BeautifulSoup/bs4/doc/#id12。