How to find tags with only certain attributes - BeautifulSoup

问题

How would I, using BeautifulSoup, search for tags containing ONLY the attributes I search for?

For example, I want to find all <td valign="top"> tags.

The following code: raw_card_data = soup.fetch('td', {'valign':re.compile('top')})

gets all of the data I want, but also grabs any <td> tag that has the attribute valign:top

I also tried: raw_card_data = soup.findAll(re.compile('<td valign="top">')) and this returns nothing (probably because of bad regex)

I was wondering if there was a way in BeautifulSoup to say "Find <td> tags whose only attribute is valign:top"

UPDATE FOr example, if an HTML document contained the following <td> tags:

<td valign="top">.....</td><br />
<td width="580" valign="top">.......</td><br />
<td>.....</td><br />

I would want only the first <td> tag (<td width="580" valign="top">) to return

回答1:

As explained on the BeutifulSoup documentation

You may use this :

soup = BeautifulSoup(html)
results = soup.findAll("td", {"valign" : "top"})

EDIT :

To return tags that have only the valign="top" attribute, you can check for the length of the tag attrs property :

from BeautifulSoup import BeautifulSoup

html = '<td valign="top">.....</td>\
        <td width="580" valign="top">.......</td>\
        <td>.....</td>'

soup = BeautifulSoup(html)
results = soup.findAll("td", {"valign" : "top"})

for result in results :
    if len(result.attrs) == 1 :
        print result

That returns :

<td valign="top">.....</td>

回答2:

You can use lambda functions in findAll as explained in documentation. So that in your case to search for td tag with only valign = "top" use following:

td_tag_list = soup.findAll(
                lambda tag:tag.name == "td" and
                len(tag.attrs) == 1 and
                tag["valign"] == "top")

回答3:

if you want to only search with attribute name with any value

from bs4 import BeautifulSoup
import re

soup= BeautifulSoup(html.text,'lxml')
results = soup.findAll("td", {"valign" : re.compile(r".*")})

as per Steve Lorimer better to pass True instead of regex

results = soup.findAll("td", {"valign" : True})

回答4:

The easiest way to do this is with the new CSS style select method:

soup = BeautifulSoup(html)
results = soup.select('td[valign="top"]')

回答5:

Just pass it as an argument of findAll:

>>> from BeautifulSoup import BeautifulSoup
>>> soup = BeautifulSoup("""
... <html>
... <head><title>My Title!</title></head>
... <body><table>
... <tr><td>First!</td>
... <td valign="top">Second!</td></tr>
... </table></body><html>
... """)
>>>
>>> soup.findAll('td')
[<td>First!</td>, <td valign="top">Second!</td>]
>>>
>>> soup.findAll('td', valign='top')
[<td valign="top">Second!</td>]

回答6:

Adding a combination of Chris Redford's and Amr's answer, you can also search for an attribute name with any value with the select command:

from bs4 import BeautifulSoup as Soup
html = '<td valign="top">.....</td>\
    <td width="580" valign="top">.......</td>\
    <td>.....</td>'
soup = Soup(html, 'lxml')
results = soup.select('td[valign]')

来源：https://stackoverflow.com/questions/8933863/how-to-find-tags-with-only-certain-attributes-beautifulsoup

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python

beautifulsoup