How to Write XML File in Python: Simple Guide

To write an XML file in Python, use the xml.etree.ElementTree module to create elements and then write them to a file with ElementTree.write(). This method builds the XML structure in memory and saves it as a file.

Syntax

Use xml.etree.ElementTree to create XML elements and build a tree. Then use ElementTree.write(filename) to save the XML to a file.

• Element(tag): Creates an XML element with the given tag.
• SubElement(parent, tag): Creates a child element under a parent.
• ElementTree(element): Wraps the root element to manage the tree.
• write(filename): Saves the XML tree to a file.

python

import xml.etree.ElementTree as ET

root = ET.Element('root')  # Create root element
child = ET.SubElement(root, 'child')  # Create child element
child.text = 'Hello XML'  # Add text to child

tree = ET.ElementTree(root)  # Create tree from root

tree.write('output.xml', encoding='utf-8', xml_declaration=True)  # Write XML to file

Example

This example creates a simple XML file with a root and two child elements, then writes it to example.xml. It shows how to add tags and text content.

python

import xml.etree.ElementTree as ET

# Create root element
root = ET.Element('library')

# Add first book element
book1 = ET.SubElement(root, 'book')
book1.set('id', '1')
title1 = ET.SubElement(book1, 'title')
title1.text = 'Python Basics'
author1 = ET.SubElement(book1, 'author')
author1.text = 'Alice'

# Add second book element
book2 = ET.SubElement(root, 'book')
book2.set('id', '2')
title2 = ET.SubElement(book2, 'title')
title2.text = 'Learning XML'
author2 = ET.SubElement(book2, 'author')
author2.text = 'Bob'

# Create tree and write to file
tree = ET.ElementTree(root)
tree.write('example.xml', encoding='utf-8', xml_declaration=True)

Common Pitfalls

Common mistakes when writing XML files in Python include:

• Not setting encoding and xml_declaration=True in write(), which can cause encoding issues or missing XML headers.
• Forgetting to add text content to elements, resulting in empty tags.
• Not using SubElement properly, which can break the XML structure.
• Trying to write the tree before building the full structure.

python

import xml.etree.ElementTree as ET

# Wrong: Missing encoding and declaration
root = ET.Element('root')
child = ET.SubElement(root, 'child')
child.text = 'data'
tree = ET.ElementTree(root)
tree.write('bad.xml')  # No encoding or XML declaration

# Right: Add encoding and declaration

tree.write('good.xml', encoding='utf-8', xml_declaration=True)

Quick Reference

Summary tips for writing XML files in Python:

• Use Element and SubElement to build XML structure.
• Set element text with element.text = 'your text'.
• Use ElementTree.write(filename, encoding='utf-8', xml_declaration=True) to save properly.
• Check the XML file after writing to ensure correct format.

Key Takeaways

Use xml.etree.ElementTree to create and write XML files in Python.

Always include encoding and xml_declaration when writing to file.

Build the full XML tree before writing to avoid incomplete files.

Use SubElement to add child elements properly under a parent.

Set text content on elements to include data inside tags.