Python XML Parsing with xml.etree.ElementTree and xml.dom.minidom

Python provides two built‑in modules for working with XML: xml.etree.ElementTree (a lightweight tree API) and xml.dom.minidom (a minimal DOM implementation). Both can read XML from files or strings, navigate the hierarchical structure, and modify the document.

What is XML? XML (eXtensible Markup Language) is a markup language for representing structured data, similar in appearance to HTML but designed for data interchange between client and server.

Example XML file Sample.xml used throughout the tutorial:

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
    <food>
        <item name="breakfast">Idly</item>
        <price>$2.5</price>
        <description>Two idly's with chutney</description>
        <calories>553</calories>
    </food>
    ... (other food items) ...
</metadata>

Using xml.etree.ElementTree

Parse a file with parse() :

import xml.etree.ElementTree as ET
mytree = ET.parse('sample.xml')
myroot = mytree.getroot()

Parse a string with fromstring() :

import xml.etree.ElementTree as ET
data = '''<?xml version="1.0" encoding="UTF-8"?>
<metadata>
    <food>
        <item name="breakfast">Idly</item>
        <price>$2.5</price>
        <description>Two idly's with chutney</description>
        <calories>553</calories>
    </food>
</metadata>'''
myroot = ET.fromstring(data)
print(myroot.tag)

Access root element, child tags, and text:

print(myroot)                     # <Element 'metadata' at 0x...>
print(myroot[0].tag)               # food
for x in myroot[0]:
    print(x.tag, x.attrib)        # item {'name': 'breakfast'} etc.
for x in myroot[0]:
    print(x.text)                 # Idly, $2.5, Two idly's with chutney, 553

Find specific elements and attributes:

for x in myroot.findall('food'):
    item = x.find('item').text
    price = x.find('price').text
    print(item, price)

Modify XML – add, update, or delete nodes:

# Add a new attribute to each description
for description in myroot.iter('description'):
    new_desc = description.text + ' will be served'
    description.text = new_desc
    description.set('updated', 'yes')
mytree.write('new.xml')

# Add a new sub‑element
ET.SubElement(myroot[0], 'speciality')
for x in myroot.iter('speciality'):
    x.text = 'South Indian Special'
mytree.write('output5.xml')

# Delete an attribute
myroot[0][0].attrib.pop('name', None)
mytree.write('output5.xml')

# Remove a child element
myroot[0].remove(myroot[0][0])
mytree.write('output6.xml')

# Clear all children of a tag
myroot[0].clear()
mytree.write('output7.xml')

Using xml.dom.minidom

Parse a file with parse() :

from xml.dom import minidom
p1 = minidom.parse('sample.xml')
print(p1)

Parse a string with parseString() :

p3 = minidom.parseString('<myxml>Using<empty/> parseString</myxml>')
print(p3)

Access elements by tag name:

dat = minidom.parse('sample.xml')
item_node = dat.getElementsByTagName('item')[0]
print(item_node)                     # <DOM Element: item at ...>
print(item_node.attributes['name'].value)   # breakfast
print(item_node.firstChild.data)            # Idly

Iterate over all items and count them:

items = dat.getElementsByTagName('item')
for x in items:
    print(x.firstChild.data)
print('Total items:', len(items))

The article concludes with a brief promotion for a free Python public course and links to related tutorials.