Python XML Processing Tutorial – Parse, Create, and Modify XML Data

Python XML Processing

XML (eXtensible Markup Language) is a widely used format for storing and transporting structured data.

It is commonly used in:

• Web services (SOAP APIs)
• Configuration files
• Data exchange systems
• Mobile and desktop applications
• Document storage

Python provides built-in modules to easily work with XML data.

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What is XML?

XML is a markup language used to define data in a structured format.

Example XML:

<user>
    <name>John</name>
    <age>30</age>
    <city>New York</city>
</user>

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Why Use XML?

• Platform independent
• Human-readable
• Structured data format
• Widely supported in APIs
• Easy data sharing between systems

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Python XML Modules

Python provides two main modules:

1. xml.etree.ElementTree (recommended)
2. xml.dom.minidom

We will focus on ElementTree.

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1. Parsing XML in Python

import xml.etree.ElementTree as ET

xml_data = """
<user>
    <name>John</name>
    <age>30</age>
    <city>New York</city>
</user>
"""

root = ET.fromstring(xml_data)

print(root.tag)

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Output

user

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Accessing XML Elements

print(root.find("name").text)
print(root.find("age").text)

Output:

John
30

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2. Reading XML from File

Example XML File (data.xml)

<users>
    <user>
        <name>Alice</name>
        <age>25</age>
    </user>
</users>

Python Code:

import xml.etree.ElementTree as ET

tree = ET.parse("data.xml")
root = tree.getroot()

for user in root.findall("user"):
    name = user.find("name").text
    age = user.find("age").text
    print(name, age)

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3. Creating XML in Python

import xml.etree.ElementTree as ET

root = ET.Element("users")

user = ET.SubElement(root, "user")
name = ET.SubElement(user, "name")
age = ET.SubElement(user, "age")

name.text = "John"
age.text = "30"

tree = ET.ElementTree(root)
tree.write("output.xml")

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Output XML

<users>
    <user>
        <name>John</name>
        <age>30</age>
    </user>
</users>

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4. Modifying XML Data

import xml.etree.ElementTree as ET

tree = ET.parse("data.xml")
root = tree.getroot()

for age in root.iter("age"):
    age.text = "35"

tree.write("updated.xml")

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5. Adding New Elements

new_user = ET.SubElement(root, "user")

name = ET.SubElement(new_user, "name")
name.text = "Bob"

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6. Deleting XML Elements

for user in root.findall("user"):
    name = user.find("name").text
    if name == "Alice":
        root.remove(user)

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7. Using xml.dom.minidom

For pretty printing XML:

from xml.dom import minidom

xml = "<root><name>John</name></root>"

dom = minidom.parseString(xml)

print(dom.toprettyxml())

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Output

<root>
    <name>John</name>
</root>

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8. XML Attributes

import xml.etree.ElementTree as ET

root = ET.Element("user", id="101")

name = ET.SubElement(root, "name")
name.text = "John"

print(ET.tostring(root))

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9. Working with Namespaces

import xml.etree.ElementTree as ET

xml = """<ns:user xmlns:ns="http://example.com">
    <ns:name>John</ns:name>
</ns:user>"""

root = ET.fromstring(xml)

print(root.tag)

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10. XPath in XML

import xml.etree.ElementTree as ET

tree = ET.parse("data.xml")
root = tree.getroot()

users = root.findall(".//user")

for user in users:
    print(user.find("name").text)

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XML vs JSON

Feature	XML	JSON
Format	Tag-based	Key-value
Readability	Medium	High
File size	Larger	Smaller
Speed	Slower	Faster
Usage	Legacy systems	Modern APIs

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Real-World Applications

XML is used in:

• Web services (SOAP APIs)
• Configuration files
• Microsoft Office files
• Android layouts
• Data exchange systems
• Enterprise applications

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Best Practices

• Use ElementTree for simplicity
• Validate XML structure
• Avoid deep nesting
• Use namespaces properly
• Handle parsing errors

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Common Errors

Parse Error

xml.etree.ElementTree.ParseError

Solution:

• Check XML syntax

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File Not Found

Ensure XML file path is correct.

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Summary

Python provides powerful built-in tools for XML processing using modules like ElementTree and minidom. These tools allow developers to parse, create, and modify XML data efficiently.

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Conclusion

XML remains an important data format in many systems. Python makes XML processing simple and efficient, allowing developers to handle structured data in web services, configuration files, and enterprise applications.