如何获得“汤"并串联/加入它们? [英] How to get "subsoups" and concatenate/join them?
问题描述
我有一个需要处理的HTML文档.我正在为此使用"beautifoulsoup".现在，我想从该文档中检索一些子汤"，并将它们加入一个汤中，以便以后可以将其用作需要汤对象的函数的参数.
I have a HTML document I need to process. I'm using 'beautifoulsoup' for that. Now I would like to retrieve a few "subsoups" from that document and join them into one soup so I can later use it as a parameter for a function that expects a soup object.
如果不清楚，我给你举个例子...
If it's not clear, I'll give you an example...
from bs4 import BeautifulSoup
my_document = """
<html>
<body>
<h1>Some Heading</h1>
<div id="first">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<p>A paragraph.</p>
</div>
<div id="second">
<p>A paragraph.</p>
<p>A paragraph.</p>
</div>
<div id="third">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<a href="yet_another_doc.html">A link</a>
</div>
<p id="loner">A paragraph.</p>
</body>
</html>
"""
soup = BeautifulSoup(my_document)
# find the needed parts
first = soup.find("div", {"id": "first"})
third = soup.find("div", {"id": "third"})
loner = soup.find("p", {"id": "loner"})
subsoups = [first, third, loner]
# create a new (sub)soup
resulting_soup = do_some_magic(subsoups)
# use it in a function that expects a soup object and calls its methods
function_expecting_a_soup(resulting_soup)
目标是在resulting_soup中创建一个对象，使其具有以下内容:
The goal is to have an object in resulting_soup that is/behaves like a soup with the following content:
<div id="first">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<p>A paragraph.</p>
</div>
<div id="third">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<a href="yet_another_doc.html">A link</a>
</div>
<p id="loner">A paragraph.</p>
是否有方便的方法来做到这一点?如果有比"find()"更好的方法来检索"subsoups"，我可以改用它.谢谢.
Is there a convenient way to do that? If there is a better way to retrieve the "subsoups" than find(), I can use it instead. Thanks.
更新
Wondercricket建议使用解决方案，该解决方案将包含找到的标签的字符串连接起来，然后再次将其解析为新的BeautifulSoup对象.尽管这是解决问题的一种可能方法，但是重新解析可能要比我想要的时间长，尤其是当我想检索其中的大部分文档并且需要处理许多此类文档时. find()返回bs4.element.Tag.没有办法将几个Tag连接成一个汤而不将Tag转换成字符串并解析该字符串吗?
There is a solution advised by Wondercricket that concatenates strings containing the found tags and parses them again into a new BeautifulSoup Object. While it's a possible way to solve the problem, the re-parsing may take longer than I'd like especially when I want to retrieve the most of them and there are many such documents I need to process. find() returns a bs4.element.Tag. Isn't there a way how to concatenate several Tags into one soup without converting the Tags to a string and parsing the string?
推荐答案
SoupStrainer would do exactly what you are asking about and, as a bonus, you'll get a performance boost since it would parse exactly what you want it to parse - not the complete document tree:
from bs4 import BeautifulSoup, SoupStrainer
parse_only = SoupStrainer(id=["first", "third", "loner"])
soup = BeautifulSoup(my_document, "html.parser", parse_only=parse_only)
现在，soup对象将仅包含所需的元素:
Now, the soup object would contain only the desired elements:
<div id="first">
<p>
A paragraph.
</p>
<a href="another_doc.html">
A link
</a>
<p>
A paragraph.
</p>
</div>
<div id="third">
<p>
A paragraph.
</p>
<a href="another_doc.html">
A link
</a>
<a href="yet_another_doc.html">
A link
</a>
</div>
<p id="loner">
A paragraph.
</p>
是否还可以不仅指定ID，还可以指定标签?例如，如果我想过滤所有带有class ="someclass的段落，但不过滤具有相同类别的div?
Is it also possible to specify not only ids but also tags? For example if I want to filter all paragraphs with class="someclass but not divs with the same class?
在这种情况下，您可以创建搜索功能以加入SoupStrainer的多个条件:
In this case, you can make a search function to join multiple criteria for the SoupStrainer:
from bs4 import BeautifulSoup, SoupStrainer, ResultSet
my_document = """
<html>
<body>
<h1>Some Heading</h1>
<div id="first">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<p>A paragraph.</p>
</div>
<div id="second">
<p>A paragraph.</p>
<p>A paragraph.</p>
</div>
<div id="third">
<p>A paragraph.</p>
<a href="another_doc.html">A link</a>
<a href="yet_another_doc.html">A link</a>
</div>
<p id="loner">A paragraph.</p>
<p class="myclass">test</p>
</body>
</html>
"""
def search(tag, attrs):
if tag == "p" and "myclass" in attrs.get("class", []):
return tag
if attrs.get("id") in ["first", "third", "loner"]:
return tag
parse_only = SoupStrainer(search)
soup = BeautifulSoup(my_document, "html.parser", parse_only=parse_only)
print(soup.prettify())
这篇关于如何获得“汤"并串联/加入它们?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
