Pfthb

I need to rearrange / combine XML files to a new target file.

My data has the following form

<?xml version="1.0" encoding="utf-8"?>
<Level1>
 <Level2>
 <Level3>
 <ID>1</ID>
 <Name>String1</Name>
 <Attribute>123</Attribute>
 </Level3>
 <Level3>
 <ID>2</ID>
 <Name>String2</Name>
 <Attribute>456</Attribute>
 </Level3>
 <Level3>
 <ID>3</ID>
 <Name>String3</Name>
 <Attribute>789</Attribute>
 </Level3>
 </Level2>
</Level1>

I'm looking for a python command to get a block of Level3 via the ID, for example

getBlock(2) should deliver

<Level3>
 <ID>2</ID>
 <Name>String2</Name>
 <Attribute>456</Attribute>
</Level3>

Thanks in advance

Here's another example of using ElementTree, but without doing all of the unnecessary for loops. The testing of the ID value can be done in a simple XPath predicate.

Example (super basic with no error checking)

import xml.etree.ElementTree as ET

xml = """<Level1>
 <Level2>
 <Level3>
 <ID>1</ID>
 <Name>String1</Name>
 <Attribute>123</Attribute>
 </Level3>
 <Level3>
 <ID>2</ID>
 <Name>String2</Name>
 <Attribute>456</Attribute>
 </Level3>
 <Level3>
 <ID>3</ID>
 <Name>String3</Name>
 <Attribute>789</Attribute>
 </Level3>
 </Level2>
</Level1>"""

tree = ET.fromstring(xml)

def getBlock(xml_tree, id):
 return xml_tree.find(f".//Level3[ID='id']")

print(ET.tostring(getBlock(tree, "2"), encoding="unicode"))

this will print:

<Level3>
 <ID>2</ID>
 <Name>String2</Name>
 <Attribute>456</Attribute>
</Level3>

If you'd like to use more complicated XPath, I'd recommend lxml since ElementTree's XPath support is limited.

You can use Python's XML library to do this. The following is a code snippet to show one way of obtaining an XML block based on its children's value.

import xml.etree.ElementTree as ET

# Parse XML file, creates ElementTree object
tree = ET.parse("<XML_FILEPATH_HERE>")
root = tree.getroot()

# Get <Level3> nodes with specific id within XML ElementTree object
def getBlock(root, id_value):
 for lvl_3 in root.findall('.//Level3'):
 if id_value == lvl_3.find('ID').text:
 print(ET.tostring(lvl_3).decode())

You can check out the python XML library document for more information.
https://docs.python.org/3/library/xml.etree.elementtree.html

The xml.etree.ElementTree package can do that for you.

Import your data from either string or file

Level1 = ET.fromstring(myXml) 

And you'll have a tree in the form of a list of lists.

Iterating, selecting or filtering over these lists becomes easy. This iterates across a list of all Level3 elements:

Level1 = ET.fromstring(myXml)

for Level3 in Level1.findall('.//Level3'):
 for child in Level3:
 print (child.tag, child.text)