Python xml find element by tag value

I am using python xmlElementTree and want to assign or modify a xml element value based on its attribute. Can somebody give me an idea how to do this?

For example: Here is a xml file and I need to set the value for the element "number" based on the attribute "sys/phoneNumber/1", "sys2/SMSnumber/1" and so on.

edit: Added closure for the tag root in the XML file.

1stthomas

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asked Mar 21, 2012 at 1:03

You can access the attribute value as this:

from elementtree.ElementTree import XML, SubElement, Element, tostring

text = """

    
        
        
        
    

    
        
        
    

"""

elem = XML[text]
for node in elem.find['phoneNumbers']:
    print node.attrib['topic']
    # Create sub elements
    if node.attrib['topic']=="sys/phoneNumber/1":
        tag = SubElement[node,'TagName']
        tag.attrib['attr'] = 'AttribValue'

print tostring[elem]

forget to say, if your ElementTree version is greater than 1.3, you can use XPath:

elem.find['.//number[@topic="sys/phoneNumber/1"]']

//effbot.org/zone/element-xpath.htm

or you can use this simple one:

for node in elem.findall['.//number']:
    if node.attrib['topic']=="sys/phoneNumber/1":
        tag = SubElement[node,'TagName']
        tag.attrib['attr'] = 'AttribValue'

answered Mar 21, 2012 at 1:35

focusheartfocusheart

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4

For me this Elementtree snipped of code worked to find element by attribute:

import xml.etree.ElementTree as ET
tree = ET.parse['file.xml']
root = tree.getroot[]


topic=root.find[".//*[@topic='sys/phoneNumber/1']"].text

answered Feb 28, 2019 at 20:15

Eduard FlorinescuEduard Florinescu

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I'm not familiar with xmlElementTree, but if you're using something capable of xpath expressions you can locate a node by attribute value using an expression like this:

//number[@topic="sys/phoneNumber/1"]

So, using the etree module:

>>> import lxml.etree as etree
>>> doc = etree.parse['foo.xml']
>>> nodes = doc.xpath['//number[@topic="sys/phoneNumber/1"]']
>>> nodes
[]
>>> etree.tostring[nodes[0]]
'\n    '

answered Mar 21, 2012 at 1:16

larskslarsks

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larsks explains how to use XPath to find what you are after very well. You also wanted to change an attribute. The best way is probably to add a new attribute and remove the original. Once you get the nodes result, it is a list with a single entry [number].

# This returns sys/phoneNumber/1
nodes[0].get["topic"]
# To change the value, use set 
nodes[0].set["topic", "new/value/of/phone/number"]

Hope this helps.

Also, your ending root tag doesn't close properly.

answered Mar 21, 2012 at 1:58

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