使用Beautifulsoup的带有空格的类的正则表达式 [英] Regular expression for class with whitespaces using Beautifulsoup

问题描述

我发现方法BeautifulSoup.find()将空格分隔的类属性. 在那种情况下，我不能使用正则表达式，如下面的代码所示. 有人可以帮我找到所有树童"元素的正确方法吗?

I found that method BeautifulSoup.find() splits class attribute by whitespaces. In that case I couldn't use regular expression as show in code below. Could you somebody help me to get right way find all 'tree children' elements:

import re
from bs4 import BeautifulSoup 

r_html = "<div class='root'>" \
       "<div class='tree children1'>text children 1 </div>" \
       "<div class='tree children2'>text children 2 </div>" \
       "<div class='tree children3'>text children 3 </div>" \
   "</div>"

bs_tab = BeautifulSoup(r_html, "html.parser")
workspace_box_visible = bs_tab.findAll('div', {'class':'tree children1'})
print workspace_box_visible # result: [<div class="tree children1">textchildren 1 </div>]
workspace_box_visible = bs_tab.findAll('div', {'class':re.compile('^tree children\d')})
print workspace_box_visible # result: [] >>>> empty array because 
                                         #class name was splited by whitespace character<<<<

# >>>>>> print all element classes <<<<<<<
def print_class(class_):
    print class_
    return False

workspace_box_visible = bs_tab.find('div', {'class': print_class})

# expected: 
# root
# tree children1
# tree children2
# tree children3

# actual:
# root
# tree
# children1
# tree
# children2
# tree
# children3

预先感谢

====注释=========

==== comments ==========

stackoverflow网站不允许添加注释超过500个字符， 所以我在这里添加了评论:

stackoverflow site don't allow add comments more than 500 characters, so I added comments here:

上面是一个示例，展示了BeautifulSoup如何查找所需的类.

Above, it was example to show how to BeautifulSoup looking for required classes.

但是，如果我具有DOM结构，例如:

But, If I have DOM structure like:

 r_html = "<div class='root'>" \
       "<div class='tree children'>zero</div>" \
       "<div class='tree children first'>first</div>" \
       "<div class='tree children second'>second</div>" \
       "<div class='tree children third'>third</div>" \
   "</div>"

以及何时需要选择具有类属性的控件:" 树上的孩子 "和" 树上的孩子优先 '， 您(Padraic Cunningham)帖子中描述的所有方法均无效.

and when need to select controls with class attributes: 'tree children' and 'tree children first', All of the methods described in your(Padraic Cunningham) post aren't work.

我找到了使用正则表达式的解决方案:

I found a solution with using regex:

controls = bs_tab.findAll('div')
for control in controls:
    if re.search("^tree children|^tree children first", " ".join(control.attrs['class']  if control.attrs.has_key('class') else "")):
    print control

和另一种解决方案:

bs_tab.findAll('div', class_='tree children') + bs_tab.findAll('div', class_='tree children first')

我知道，这不是一个好的解决方案.我希望BeautifulSoup模块有合适的方法.

I know, it's not good solution. and I hope that BeautifulSoup module has appropriate method for that.

推荐答案

根据html的结构，有几种不同的方法，它们是css类，因此您可以使用class_=..或使用.选择:

There are a few different ways depending on the structure of the html, they are css classes so you could just use class_=.. or a css selector using .select:

In [3]: bs_tab.find_all('div', class_="tree")
Out[3]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
 <div class="tree children3">text children 3 </div>]

In [4]: bs_tab.select("div.tree")
Out[4]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
 <div class="tree children3">text children 3 </div>]

但是如果您在其他地方还有另一个 tree 类，也会找到.

But if you had another tree class elsewhere that would find then also.

您可以使用选择器来查找包含子级的div:

You could use a selector to find divs that contains children in the class:

In [5]: bs_tab.select("div[class*=children]") 
Out[5]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
 <div class="tree children3">text children 3 </div>]

但是，如果还有其他带有孩子名称的标记类，它们也会被选中.

But again if there were other tag classes with children in the name they would also be picked up.

使用正则表达式可能会更具体一些，并寻找 children ，后跟一个或多个数字:

You could be a bit more specific with a regex and look for children followed by one or more digits:

In [6]: bs_tab.find_all('div', class_=re.compile("children\d+"))
Out[6]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
 <div class="tree children3">text children 3 </div>]

或者找到所有 div.tree的，然后查看 tag ["class"] starstwith children .

Or find all the div.tree's and see if the last names in tag["class"] starstwith children.

In [7]: [t for t in bs_tab.select("div.tree") if t["class"][-1].startswith("children")]
Out[7]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
 <div class="tree children3">text children 3 </div>]

或者寻找孩子，看看第一个css类名称是否等于 tree

Or look for children and see if the first css class name is equal to tree

In [8]: [t for t in bs_tab.select("div[class*=children]") if t["class"][0] == "tree"]
Out[8]: 
[<div class="tree children1">text children 1 </div>,
 <div class="tree children2">text children 2 </div>,
<div class="tree children3">text children 3 </div>]

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