Python是查找标记最有效的方法

我正在使用python和BeautifulSoup解析许多大型XML文件。我经常遇到以下任务：

<Section1>
    <Report>
        <Matrix>...</Matrix>
        <Matrix>...</Matrix>
        <Matrix>...</Matrix>
        <Matrix>...</Matrix>
    </Report>
</Section1>

为什么我不能使用这样的选择器

matrices = soup.find("Section1 Matrix")

有没有更快的方法？有时，我访问嵌套在XML中更远的节点，我需要确保它们是后代，但不一定是其他几个节点的直接子节点。提供的示例a是一个简化。任何帮助都将不胜感激

美化组您需要将选择器传递到

。选择
方法

In [1]: from bs4 import BeautifulSoup as BS

In [2]: soup = BS("""<Section1>
   ...:     <Report>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:     </Report>
   ...: </Section1>""", "xml")

In [3]: soup.select("Section1 Matrix")
Out[3]: 
[<Matrix>...</Matrix>,
 <Matrix>...</Matrix>,
 <Matrix>...</Matrix>,
 <Matrix>...</Matrix>]


1如果cssselect尚未与pip一起安装，则需要安装它：
pip安装cssselect
是否尝试使用lxml？这将大大提高性能。
In [1]: from bs4 import BeautifulSoup as BS

In [2]: soup = BS("""<Section1>
   ...:     <Report>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:     </Report>
   ...: </Section1>""", "xml")

In [3]: soup.select("Section1 Matrix")
Out[3]: 
[<Matrix>...</Matrix>,
 <Matrix>...</Matrix>,
 <Matrix>...</Matrix>,
 <Matrix>...</Matrix>]

In [3]: from lxml.etree import fromstring

In [4]: xml_doc = '''<Section1>
   ...:     <Report>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:         <Matrix>...</Matrix>
   ...:     </Report>
   ...: </Section1>'''

In [5]: tree = fromstring(xml_doc)

In [6]: matrix = [el for el in sel(tree)]

In [7]: matrix
Out[7]: 
[<Element Matrix at 0x7f84b5b8f388>,
 <Element Matrix at 0x7f84b5b8fc48>,
 <Element Matrix at 0x7f84b5b8fd88>,
 <Element Matrix at 0x7f84b5b8fdc8>]