Python/Pandas：从 Pandas DataFrame 更新 XML 文件

Question

我正在尝试使用 Pandas DataFrame 中的数据更新 xml 文件：xml 文件如下所示：

<root>
    <NetworkData>
        <Element loadid="23" type="Load" node1="N23">
            <Name>load1</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>11</x>
            <y>15</y>
        </Element>
        <Element loadid="24" type="Load" node1="N24">
            <Name>load2</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>0.75</x>
            <y>600</y>
        </Element>
        ...

数据框看起来像：

ID	X	是
23	17	29
24	123	543
...	...	...

该ID与 xml 文件中的loadid相同。 我的目标是使用 Dataframe 中的值更新 xml 文件中的值x和y 。 有没有一种简单的方法可以做到这一点，因为 Dataframe 很长？ 顺便说一下，所有loadids都可以在 Dataframe 中作为IDs找到。 输出 xml 文件：

  <root>
    <NetworkData>
        <Element loadid="23" type="Load" node1="N23">
            <Name>load1</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>17</x>
            <y>29</y>
        </Element>
        <Element loadid="24" type="Load" node1="N24">
            <Name>load2</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>123</x>
            <y>543</y>
        </Element>
        ...

谢谢！

Answer 1

import pandas as pd
from lxml import etree

# create test dataframe
df = pd.DataFrame({
    'ID': [23,24,25,26,27],
    'x': [21,22,23,24,25],
    'y': [101,102,103,104,105]
})

# create xml as a string (in your code it could be a file)
text = '''<root>
    <NetworkData>
        <Element loadid="23" type="Load" node1="N23">
            <Name>load1</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>11</x>
            <y>15</y>
        </Element>
        <Element loadid="24" type="Load" node1="N24">
            <Name>load2</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>0.75</x>
            <y>600</y>
        </Element>
        <Element loadid="99" type="Load" node1="N24">
            <Name>load2</Name>
            <ShortName/>
            <InputState>1027</InputState>
            <x>0.75</x>
            <y>600</y>
        </Element>
    </NetworkData>
  </root>
'''

# convert string to xml 
# (in your code it could be read from file instead)
doc = etree.fromstring(text)

# iterate over elements "Element"
for el in doc.xpath(".//NetworkData/Element"):
  # retrieve id from attribute value
  id = el.get('loadid')
  # retrieve appropriate row from dataframe
  row = df[df['ID'] == int(id)]
  # if found, update x and y
  if len(row) == 1:
      # find "x" element
      x = el.find('./x')
      # if found, update
      if x is not None:
        x.text = str(row['x'].item())
      # find "y" element
      y = el.find('./y')
      # if found update
      if y is not None:
        y.text = str(row['y'].item())
  # if there was no match found, update x and y with "0" values
  elif len(row) == 0:
      # find "x" element
      x = el.find('./x')
      # if found, update
      if x is not None:
        x.text = '0'
      # find "y" element
      y = el.find('./y')
      # if found update
      if y is not None:
        y.text = '0'

# save changed XML
# ...