使用python从多次出现的xml文件中删除特定元素

大家好，我的社区

如果能给我一些指导，帮助我使用Python和elementTree库调整XML文件，我将不胜感激

目前，我有以下file.xml文件：

<component xmlns:xsi="http://www.w3.orgr">
  <memoryMaps>
    <memoryMap>
      <name>name</name>
      <description>description</description>
      <peripheral>
        <name>periph</name>
        <description>description</description>
        <baseAddress>0x0</baseAddress>
        <range>0x8</range>
        <width>32</width>
       <registers>
        <register>
          <name>reg1</name>
          <displayName>reg1</displayName>
          <description>This is register 1</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000002</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields>
           .................
         </fields>
         <resetValue>0x00000002</resetValue>
         <resetMask>0xFFFFFFFF</resetMask>
         <description>This is register 1</description>
        </register>                           
        <register>
          <name>reg2</name>
          <displayName>reg2</displayName>
          <description>This is register 2</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000000</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields>
           .................
         </fields>
         <resetValue>0x00000000</resetValue>
         <resetMask>0xFFFFFFFF</resetMask>
         <description>This is register 2</description>
         </register>
         <register>
             ..................
         </register>  
       </registers>    
      </peripheral>
    </memoryMap>
  </memoryMaps>
</component>

名称
描述
外围
描述
0x0
0x8
32
reg1
reg1
这是寄存器1
0x0
32
读写
0x00000002
0xFFFFFF
.................
0x00000002
0xFFFFFF
这是寄存器1
reg2
reg2
这是登记册2
0x0
32
读写
0x00000000
0xFFFFFF
.................
0x00000000
0xFFFFFF
这是登记册2
..................

正如您在每个“register”末尾看到的，我有3个元素：“resetValue”、“resetMask”和“description”，它们在“register”之前也存在于其他位置，但我想删除始终存在于节点“register”末尾的三个元素，我不能使用remove元素，因为我想在之前保留该元素（'resetValue'、'resetMask'和'description'）

我希望能有一个这样的结果：

<registers>
    <register>
      <name>reg1</name>
      <displayName>reg1</displayName>
      <description>This is register 1</description>
      <addressOffset>0x0</addressOffset>
      <size>32</size>
      <access>read-write</access>
      <resetValue>0x00000002</resetValue>
      <resetMask>0xFFFFFFFF</resetMask>
     <fields>
       .................
     </fields>
    </register>                           
    <register>
     <name>reg2</name>
     <displayName>reg2</displayName>
     <description>This is register 2</description>
     <addressOffset>0x0</addressOffset>
     <size>32</size>
     <access>read-write</access>
     <resetValue>0x00000000</resetValue>
     <resetMask>0xFFFFFFFF</resetMask>
      <fields>
           .................
      </fields>
     </register>
     <register>
         ..................
     </register>  
   </registers> 

reg1
reg1
这是寄存器1
0x0
32
读写
0x00000002
0xFFFFFF
.................
reg2
reg2
这是登记册2
0x0
32
读写
0x00000000
0xFFFFFF
.................
..................

是否可以只删除xml中的最后一个元素？是否有索引解决方案，因为位置始终相同（每个“寄存器”末尾的最后3个元素），但元素之前存在？ 请告诉我

---

谢谢

以下是使用lxml XPath API的解决方案：

from lxml import etree as et
import itertools

# here variable xml is a string with the source XML from your question
root = et.fromstring(xml)

# create list of elements to be deleted
# itertools.chain() here creates one list from 3 lists returned by xpath() function calls
# predicate [last()] ensures that we select last element
elements = itertools.chain(
    root.xpath("//register/resetValue[last()]"),
    root.xpath("//register/resetMask[last()]"),
    root.xpath("//register/description[last()]"))

# iterate over selected elements and delete them
for el in elements:
  el.getparent().remove(el)

# output result
print (et.tostring(root, pretty_print=True, xml_declaration=True).decode('utf8'))

输出：

<?xml version='1.0' encoding='ASCII'?>
<component xmlns:xsi="http://www.w3.orgr">
  <memoryMaps>
    <memoryMap>
      <name>name</name>
      <description>description</description>
      <peripheral>
        <name>periph</name>
        <description>description</description>
        <baseAddress>0x0</baseAddress>
        <range>0x8</range>
        <width>32</width>
       <registers>
        <register>
          <name>reg1</name>
          <displayName>reg1</displayName>
          <description>This is register 1</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000002</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields/>
         </register>                           
        <register>
          <name>reg2</name>
          <displayName>reg2</displayName>
          <description>This is register 2</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000000</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields/>
         </register>
         <register>
         </register>  
       </registers>    
      </peripheral>
    </memoryMap>
  </memoryMaps>
</component>

名称
描述
外围
描述
0x0
0x8
32
reg1
reg1
这是寄存器1
0x0
32
读写
0x00000002
0xFFFFFF
reg2
reg2
这是登记册2
0x0
32
读写
0x00000000
0xFFFFFF

以下是使用lxml XPath API的解决方案：

from lxml import etree as et
import itertools

# here variable xml is a string with the source XML from your question
root = et.fromstring(xml)

# create list of elements to be deleted
# itertools.chain() here creates one list from 3 lists returned by xpath() function calls
# predicate [last()] ensures that we select last element
elements = itertools.chain(
    root.xpath("//register/resetValue[last()]"),
    root.xpath("//register/resetMask[last()]"),
    root.xpath("//register/description[last()]"))

# iterate over selected elements and delete them
for el in elements:
  el.getparent().remove(el)

# output result
print (et.tostring(root, pretty_print=True, xml_declaration=True).decode('utf8'))

输出：

<?xml version='1.0' encoding='ASCII'?>
<component xmlns:xsi="http://www.w3.orgr">
  <memoryMaps>
    <memoryMap>
      <name>name</name>
      <description>description</description>
      <peripheral>
        <name>periph</name>
        <description>description</description>
        <baseAddress>0x0</baseAddress>
        <range>0x8</range>
        <width>32</width>
       <registers>
        <register>
          <name>reg1</name>
          <displayName>reg1</displayName>
          <description>This is register 1</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000002</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields/>
         </register>                           
        <register>
          <name>reg2</name>
          <displayName>reg2</displayName>
          <description>This is register 2</description>
          <addressOffset>0x0</addressOffset>
          <size>32</size>
          <access>read-write</access>
          <resetValue>0x00000000</resetValue>
          <resetMask>0xFFFFFFFF</resetMask>
         <fields/>
         </register>
         <register>
         </register>  
       </registers>    
      </peripheral>
    </memoryMap>
  </memoryMaps>
</component>

名称
描述
外围
描述
0x0
0x8
32
reg1
reg1
这是寄存器1
0x0
32
读写
0x00000002
0xFFFFFF
reg2
reg2
这是登记册2
0x0
32
读写
0x00000000
0xFFFFFF