Modify XML file with lxml with 3 namespaces

Question

Hi I have following XML file. I am trying to change the text file in the ID tag . <ID>xxx</ID> But no matter what I try it refuses to change or give me back the value in . I am a noob

<ROOT xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsd="w3.org/2001/XMLSchema"; xmlns:xsi="w3.org/2001/XMLSchema-instance"; xmlns="asml.com/XMLSchema/XXX/v1.0">  
<ID>Some String</ID>
<AList>
    <Attribute>
        <Name>SomeName</Name>
        <Value>SomeValue</Value>
    </Attribute>
    <Attribute>
        <Name>SomeName_2</Name>
        <Value>SomeValue_2</Value>
    </Attribute>
    <Attribute>
        <Name>SomeName_3</Name>
        <Value>SomeValue_3</Value>
    </Attribute>
</AList>
<AGroupList>
    <Group>
        <GroupKeyList>
            <Attribute>
                <Name>SomeName_4</Name>
                <Value>SomeValue_4</Value>
            </Attribute>
        </GroupKeyList>
        <GroupAList>
            <Attribute>
                <Name>SomeName_5</Name>
                <Value>SomeValue_5</Value>
            </Attribute>
        </GroupAList>
    </Group>
    <Group>
        <GroupKeyList>
            <Attribute>
                <Name>SomeName_6</Name>
                <Value>SomeValue_6</Value>
            </Attribute>
        </GroupKeyList>
        <GroupAList>
            <Attribute>
                <Name>SomeName_7</Name>
                <Value>SomeValue_7</Value>
            </Attribute>
        </GroupAList>
    </Group>
</AGroupList>

from lxml import etree
xml_elem = etree.parse('path/to/file.xml')
id_elem = xml_elem.find('ID')
id_elem.text = 'xxx'

THis is my code, I have tried everything

Answer 1

Your XML isn't valid

Just add a </ROOT> tag at the end of your xml. Then it's as simple as:

from lxml import etree
xml_elem = etree.parse('path/to/file.xml')
id_elem = xml_elem.find('ID')
id_elem.text = 'xxx'

Answer 2

Main issue is the undeclared namespace prefix xmlns="asml.com/XMLSchema/XXX/v1.0" which unlike the others does not have a colon separated identifier. This requires you to qualify search paths like find with the URI. Do note: this is completely valid in XML files.

However, your posted markup is not well-formed as you have a duplicate prefix: xmlns:xsd and have semicolons between namespaces. Do note: this is NOT valid XML. If your actual XML <ROOT> follows the below well-formed version, the following lxml code should work to update the ID text:

XML

<ROOT xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsd2="w3.org/2001/XMLSchema"
      xmlns:xsi="w3.org/2001/XMLSchema-instance" xmlns="asml.com/XMLSchema/XXX/v1.0">  
...
</ROOT>

Python

from lxml import etree

xml_elem = etree.parse('AGroupList.xml')
id_elem = xml_elem.find('{asml.com/XMLSchema/XXX/v1.0}ID')    # URI MAPPING
id_elem.text = 'xxx'

print(etree.tostring(xml_elem, pretty_print=True).decode("UTF-8"))

Output

<ROOT xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsd2="w3.org/2001/XMLSchema" xmlns:xsi="w3.org/2001/XMLSchema-instance" xmlns="asml.com/XMLSchema/XXX/v1.0">  
    <ID>xxx</ID>
    <AList>
        <Attribute>
            <Name>SomeName</Name>
            <Value>SomeValue</Value>
        </Attribute>
        <Attribute>
            <Name>SomeName_2</Name>
            <Value>SomeValue_2</Value>
        </Attribute>
        <Attribute>
            <Name>SomeName_3</Name>
            <Value>SomeValue_3</Value>
        </Attribute>
    </AList>
    <AGroupList>
        <Group>
            <GroupKeyList>
                <Attribute>
                    <Name>SomeName_4</Name>
                    <Value>SomeValue_4</Value>
                </Attribute>
            </GroupKeyList>
            <GroupAList>
                <Attribute>
                    <Name>SomeName_5</Name>
                    <Value>SomeValue_5</Value>
                </Attribute>
            </GroupAList>
        </Group>
        <Group>
            <GroupKeyList>
                <Attribute>
                    <Name>SomeName_6</Name>
                    <Value>SomeValue_6</Value>
                </Attribute>
            </GroupKeyList>
            <GroupAList>
                <Attribute>
                    <Name>SomeName_7</Name>
                    <Value>SomeValue_7</Value>
                </Attribute>
            </GroupAList>
        </Group>
    </AGroupList>
</ROOT>