Python 如何在树中插入新块？

使用Beautifulsoup，我需要读取一个KML文件，并在包含LineString部分的所有Placemark中插入一个新块

以下是KML文件：

<?xml version="1.0" encoding="utf-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document>
    <name>Document.kml</name>
    <Placemark>
      <name>My track</name>
      <LineString>
        <coordinates>-0.376291,43.296237,199.75
        -0.377381,43.29405</coordinates>
      </LineString>
    </Placemark>
  </Document>
</kml>

以下操作不起作用：

from bs4 import BeautifulSoup as Soup

with open('input.kml') as data:
    kml_soup = Soup(data, 'lxml-xml') # Parse as XML

placemarks = kml_soup.find_all('Placemark')
for pm in placemarks:
    if pm.find('LineString'):
        print("LS found")
        
        #How to insert new elements before LineString?
        #<Style><LineStyle><width>3</width></LineStyle></Style>
        style = kml_soup.new_tag("Style")
        style.string = "<LineStyle><width>3</width></LineStyle>"
        
        #AttributeError: 'NoneType' object has no attribute 'insert_before'
        pm.string.insert_before(style)

---

谢谢。

您可能使用了错误的对象。尝试以下方法

placemarks = kml_soup.find_all('Placemark')
for pm in placemarks:
    LineString = pm.find('LineString')
    if LineString:
        print("LS found")
        style = kml_soup.new_tag("Style")
        style.string = "<LineStyle><width>3</width></LineStyle>"
        LineString.insert_before(style) # Use LineString

这是另一个解决方案

from simplified_scrapy import SimplifiedDoc,utils
html = utils.getFileContent('input.kml')
doc = SimplifiedDoc(html)
placemarks = doc.selects('Placemark')
for pm in placemarks:
    LineString = pm.select('LineString')
    if LineString:
        print("LS found")
        style = "<Style><LineStyle><width>3</width></LineStyle></Style>\n"+" "*6
        LineString.insertBefore(style)
# print (doc.html)

---

谢谢，就这样。