XML with Python

Python ships with multiple XML libraries in its standard library. For most tasks, xml.etree.ElementTree is the simplest choice. For advanced processing with XPath and XSLT, the third-party lxml library is the standard tool.

Reading XML with ElementTree

import xml.etree.ElementTree as ET

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

print(root.tag)    # catalog

for product in root.findall("product"):
    pid   = product.get("id")
    name  = product.find("name").text
    price = product.find("price").text
    print(f"{pid}: {name} — INR {price}")

Parsing XML from a String

xml_data = """<catalog>
  <product id="P001">
    <name>Notebook</name>
    <price>40</price>
  </product>
</catalog>"""

root = ET.fromstring(xml_data)
for p in root:
    print(p.find("name").text)

Searching with find and findall

# First matching element
first = root.find("product")

# All matching elements
all_products = root.findall("product")

# XPath-like selectors in ElementTree
expensive = root.findall("product[price]")  # products that have a price child

# Iterate all with a condition
for p in root.findall("product"):
    if int(p.find("price").text) > 500:
        print(p.find("name").text)

Building XML with ElementTree

root = ET.Element("catalog")

product = ET.SubElement(root, "product")
product.set("id", "P001")

name = ET.SubElement(product, "name")
name.text = "Webcam"

price = ET.SubElement(product, "price")
price.text = "2499"

tree = ET.ElementTree(root)
tree.write("new_catalog.xml", xml_declaration=True, encoding="utf-8")

Using lxml for XPath

from lxml import etree

tree = etree.parse("products.xml")

# XPath query
results = tree.xpath("//product[price > 1000]/name/text()")
for name in results:
    print(name)

Key Points to Remember

• xml.etree.ElementTree is the standard, batteries-included XML library in Python.
• ET.parse() opens a file; ET.fromstring() parses an XML string.
• find() returns the first match; findall() returns a list of all matches.
• element.get("attr") reads attributes; element.text reads the text content.
• lxml adds full XPath and XSLT support and better performance for large files.