How to Modify an XML File in Python: A Comprehensive Guide

Modifying XML files in Python is a versatile feature, allowing you to update, add, or remove nodes and attributes. This guide uses Python's ElementTree library to demonstrate common XML modification tasks.

Code Breakdown:

import xml.etree.ElementTree as ET

Step 1: Import the ElementTree module, which is part of Python's standard library for handling XML files.

# Load the XML file
tree = ET.parse("sample.xml")
root = tree.getroot()

Step 2: Load the XML file into memory using ET.parse() and access the root element with getroot().

Updating Node Text

# Update text of a specific node
for student in root.findall("student"):
    id = student.find("id").text
    if id == "2":
        student.find("name").text = "Max Updated"

Explanation: This code locates the <student> node with id=2 and updates the text of the <name> child node to "Max Updated".

Adding a New Element

# Add a new child element
for student in root.findall("student"):
    grade = ET.SubElement(student, "grade")
    grade.text = "A"

Explanation: A new element <grade> is added as a child of each <student> node, with its text set to "A".

Removing an Element

# Remove a specific element
for student in root.findall("student"):
    mark = student.find("mark")
    if mark is not None:
        student.remove(mark)

Explanation: The <mark> element is removed from each <student> node if it exists.

Saving the Modified XML

# Save changes to a new XML file
tree.write("updated_sample.xml", encoding="utf-8", xml_declaration=True)

Explanation: The modified XML tree is written to a new file named updated_sample.xml, ensuring changes are saved with proper encoding.

Full Code Example:

import xml.etree.ElementTree as ET

# Load the XML file
tree = ET.parse("E:\\testing\\students.xml")
root = tree.getroot()

# Update text of a specific node
for student in root.findall("student"):
    id = student.find("id").text
    if id == "2":
        student.find("name").text = "Max Updated"

# Add a new child element
for student in root.findall("student"):
    grade = ET.SubElement(student, "grade")
    grade.text = "A"

# Remove a specific element
for student in root.findall("student"):
    mark = student.find("mark")
    if mark is not None:
        student.remove(mark)

# Save changes to a new XML file
tree.write("E:\\testing\\updated_sample.xml", encoding="utf-8", xml_declaration=True)

Sample Modified XML Output:

<students>
    <student>
        <id>1</id>
        <name>John Deo</name>
        <grade>A</grade>
    </student>
    <student>
        <id>2</id>
        <name>Max Updated</name>
        <grade>A</grade>
    </student>
</students>

Use Cases:

• Updating XML configuration files dynamically.
• Modifying API responses before further processing.
• Editing hierarchical data for specific requirements.

Conclusion:

Python's ElementTree library provides a robust way to modify XML files, enabling tasks like updating, adding, or removing elements and attributes. This tutorial provides a foundational understanding for tackling XML modification tasks effectively.

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author   Watch on YouTube

Connect: