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Python minidom

last modified March 7, 2025

In this article, we show how to use the minidom module in Python for XML parsing and creation. The minidom module offers a lightweight DOM interface for XML, part of Python's standard library.

The minidom module is useful for reading, writing, and modifying XML documents using a DOM-based approach.

Key features:

Parsing XML with minidom

This example shows how to parse an XML document using minidom.

main.py 
from xml.dom import minidom

# XML data
xml_data = """
<products>
    <product>
        <id>1</id>
        <name>Product 1</name>
        <price>10.99</price>
        <quantity>30</quantity>
    </product>
    <product>
        <id>2</id>
        <name>Product 2</name>
        <price>20.99</price>
        <quantity>130</quantity>
    </product>
</products>
"""

# Parse the XML data
doc = minidom.parseString(xml_data)

# Get all product elements
products = doc.getElementsByTagName('product')

# Iterate over product elements
for product in products:
    id = product.getElementsByTagName('id')[0].firstChild.data
    name = product.getElementsByTagName('name')[0].firstChild.data
    price = product.getElementsByTagName('price')[0].firstChild.data
    qty = product.getElementsByTagName('quantity')[0].firstChild.data
    print(f"Id: {id}, Name: {name}, Price: {price}, Quantity: {qty}")

Here, parseString parses the XML string into a DOM object. We use getElementsByTagName to find elements and extract their text with firstChild.data. 

$ python main.py
Id: 1, Name: Product 1, Price: 10.99, Quantity: 30
Id: 2, Name: Product 2, Price: 20.99, Quantity: 130

Modifying XML with minidom

This example shows how to modify an XML document using minidom.

main.py 
from xml.dom import minidom

# XML data
xml_data = """
<products>
    <product>
        <id>1</id>
        <name>Product 1</name>
        <price>10.99</price>
        <quantity>30</quantity>
    </product>
</products>
"""

# Parse the XML data
doc = minidom.parseString(xml_data)

# Modify the first product's price
product = doc.getElementsByTagName('product')[0]
price = product.getElementsByTagName('price')[0]
price.firstChild.data = '15.99'

# Add a new product
new_product = doc.createElement('product')
doc.documentElement.appendChild(new_product)
for tag, text in [('id', '2'), ('name', 'Product 2'), 
                  ('price', '30.99'), ('quantity', '200')]:
    elem = doc.createElement(tag)
    elem.appendChild(doc.createTextNode(text))
    new_product.appendChild(elem)

# Print the modified XML
print(doc.toprettyxml(indent="  "))

We modify the price by updating firstChild.data. A new product is created with createElement and text nodes are added using createTextNode.

Reading XML File with id Attribute

This example reads an XML file with id attributes using minidom.

products.xml 
<products>
    <product id="1">
        <name>Product 1</name>
        <price>10.99</price>
        <quantity>30</quantity>
    </product>
    <product id="2">
        <name>Product 2</name>
        <price>20.99</price>
        <quantity>130</quantity>
    </product>
</products>

Products have id as attributes.

main.py 
from xml.dom import minidom

file_name = 'products.xml'

# Parse the XML file
doc = minidom.parse(file_name)
products = doc.getElementsByTagName('product')

# Iterate over product elements
for product in products:
    product_id = product.getAttribute('id')
    name = product.getElementsByTagName('name')[0].firstChild.data
    price = product.getElementsByTagName('price')[0].firstChild.data
    qty = product.getElementsByTagName('quantity')[0].firstChild.data
    print(f"Id: {product_id}, Name: {name}, Price: {price}, Quantity: {qty}")

We use getAttribute to extract the id attribute and firstChild.data for element text. 

$ python main.py
Id: 1, Name: Product 1, Price: 10.99, Quantity: 30
Id: 2, Name: Product 2, Price: 20.99, Quantity: 130

Writing XML with minidom

This example creates and writes an XML document using minidom.

main.py 
from xml.dom import minidom

# Create the document
doc = minidom.Document()

# Create the root element
root = doc.createElement('products')
doc.appendChild(root)

# Create product elements
for i, (name, price, qty) in enumerate([
    ('Product 1', '10.99', '30'),
    ('Product 2', '20.99', '130')
], 1):
    product = doc.createElement('product')
    root.appendChild(product)
    for tag, text in [('id', str(i)), ('name', name), 
                      ('price', price), ('quantity', qty)]:
        elem = doc.createElement(tag)
        elem.appendChild(doc.createTextNode(text))
        product.appendChild(elem)

# Write to file with pretty printing
with open('products2.xml', 'w', encoding='utf-8') as f:
    f.write(doc.toprettyxml(indent="  "))

print("XML file created successfully with proper indentation.")

We build the XML structure with createElement and createTextNode, then write it using toprettyxml.

Source

Python minidom - Documentation

This article demonstrated using the minidom module in Python for XML parsing, modification, and creation.

Author

My name is Jan Bodnar, a passionate programmer with years of experience. I've been writing programming articles since 2007, with over 1400 articles and 8 e-books to date.

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