Question

我有一个XML文档，如下所示：

<!-- Servlet Context Listener -->
<listener>
<listener-class>
com.company.servlet.StartupShutdownListener
</listener-class>
</listener>
<!-- Servlet Class Definitions -->
<servlet>
<servlet-name>
AdminServlet
</servlet-name>
<servlet-class>
AdminServlet
</servlet-class>
<load-on-startup>
1
</load-on-startup>
</servlet>

为了使它更具人性化，我找到了indent（）函数http://effbot.org/zone/element-lib.htm#prettyprint，它使输出更好。

但是，我想进一步格式化Comment元素以使它们更容易看到。例如，只需在每个注释之前和之后添加一个额外的空行，就可以更容易地看到人类的块：

<!-- Servlet Context Listener -->

<listener>
  <listener-class>
    com.company.servlet.StartupShutdownListener
  </listener-class>
</listener>

<!-- Servlet Class Definitions -->

<servlet>
  <servlet-name>AdminServlet</servlet-name>
  <servlet-class>AdminServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
</servlet>

如何在indent（）函数中检测Comment元素？

Answer 1

在网上搜索同样问题的其他人之后，我转向了源代码（https://svn.python.org/projects/python/trunk/Lib/xml/etree/ElementTree.py）。答案很简单：

import ElementTree as ET

...

def indent(elem, level=0):    # where elem is of type ET.Element
    ....
    if elem.tag is ET.Comment:
        ...

关键是要意识到＆＃34;标签＆＃34;常规XML元素上的属性带有XML标记名称（例如，＆＃34; listener＆＃34;或＆＃34; servlet＆＃34;），对于表示XML注释的Element，它是Comment（）函数本身。

这是完整更新的indent（）函数，用于执行注释格式化，如上所示：

def indent(elem, level=0, prev_elem=None, prev_level=0):        
    i = "\n" + level*"  "        
    if len(elem):        
        if not elem.text or not elem.text.strip():        
            elem.text = i + "  "        
        if not elem.tail or not elem.tail.strip():        
            elem.tail = i        
        prev_elem_local = elem        
        prev_level_local = level        
        for elem in elem:        
            indent(elem, level+1, prev_elem_local, prev_level_local)        
            prev_elem_local = elem        
            prev_level_local = level + 1        
        if not elem.tail or not elem.tail.strip():        
            elem.tail = i        
    else:        
        if level and (not elem.tail or not elem.tail.strip()):        
            elem.tail = i        
        if elem.tag is ET.Comment:        
            if prev_level == level:        
                prev_elem.tail = "\n" + prev_elem.tail        
            elif prev_level < level:        
                prev_elem.text = "\n" + prev_elem.text        
            elem.tail = "\n" + elem.tail

在Python ElementTree中，如何判断元素是否为注释？

1 个答案: