ElementTree - Change subchild value conditionally

Question

I have just work with XML using ElementTree in my current project. I have a task to change a subchild value based on another subchild value in the same child.

I have created a code for that but somehow feel that there might be a way to improve on this readability wise and performance wise.

Here is my code,

import xml.etree.ElementTree as ET

tree = ET.ElementTree(ET.fromstring("KENT99JOHNfifthy"))
root = tree.getroot()

change_found = False

for item in root:

    for subItem in item:

        if change_found and subItem.tag == "Value":

            subItem.text = "50"
            change_found = False

        if subItem.tag == "Name" and subItem.text == "JOHN":

            change_found = True


print(ET.tostring(root, encoding='utf8', method='xml'))

As you can see from the code, when the subchild text is "JOHN" and the tag is "Name", it sets the change_found to True. Since the next subchild has a tag of Value, it made the change to the text (from fifty to 50).

The code works fine, but I believe there can be some improvement.

You can assume that the structure of the property is always in this order.

 
     Some name 
     Some value

You can also assume that there are only 1 with has a subchild "NAME" with a text "JOHN"

user_9448090 · Answer

If I understand you correctly, you can get there more simply, using xpath:

root = ET.fromstring([your string above])
for p in root.findall('.//Property'):
    if p.find('.//Name').text.strip()=="JOHN":
        p.find('.//Value').text="50"

print(ET.tostring(root).decode())

Output:

ElementTree - Change subchild value conditionally

1 Answers