Use ElementTree to easily parse XML files: 1. Use ET.parse() to read the file or ET.fromstring() to parse the string; 2. Use .find() to get the first matching child element, .findall() to get all matching elements, and obtain attributes and .text to get text content; 3. Use find() to determine whether it exists or use findtext() to set the default value; 4. Support basic XPath syntax such as './/title' or './/book[@id="1"]' for in-depth searches; 5. Add new elements through ET.SubElement(), and after modifying the content, call tree.write() to save to the file; it is also recommended to use try-except to catch ParseError exception, pay attention to syntax when handling XML with namespace, and large files can use iterparse() to save memory. This method does not require external dependencies and is suitable for common scenarios such as configuration file reading and data exchange.

Parsing XML files in Python is straightforward using the built-in xml.etree.ElementTree module, commonly referred to as ElementTree . It's lightweight, easy to use, and perfect for reading, modifying, and creating XML data.

Here's how to work with XML files using ElementTree in real-world scenarios.

1. Load and Parse an XML File

Start by importing the module and parsing an XML file from disk.

 import xml.etree.ElementTree as ET

# Parse the XML file
tree = ET.parse('data.xml')
root = tree.getroot() # Get the root element

If your XML is in a string instead of a file:

 xml_string = '''
<books>
  <book id="1">
    <title>Python Basics</title>
    <author>John Doe</author>
  </book>
</books>
&#39;&#39;&#39;

root = ET.fromstring(xml_string)

? Use ET.parse() for files, ET.fromstring() for strings.

2. Navigate and Access XML Elements

Once you have the root, you can traverse the tree using methods like .find() , .findall() , and .iter() .

Example XML:

 <library>
  <book id="1">
    <title>Learning Python</title>
    <author>Mark Smith</author>
  </book>
  <book id="2">
    <title>Data Science with Python</title>
    <author>Anna Lee</author>
  </book>
</library>

Access elements:

 # Get the first <book> element
first_book = root.find(&#39;book&#39;)

# Get all <book> elements
books = root.findall(&#39;book&#39;)

for book in books:
    title = book.find(&#39;title&#39;).text
    author = book.find(&#39;author&#39;).text
    book_id = book.get(&#39;id&#39;) # Get attribute
    print(f"ID: {book_id}, Title: {title}, Author: {author}")

? .find() returns the first matching child; .findall() returns a list.

3. Handle Attributes and Text Content

XML elements can have attributes and text. Use .get() for attributes and .text for content.

 for book in root.findall('book'):
    print("ID:", book.get('id')) # Attribute
    print("Title:", book.find('title').text) # Text inside child

If a tag might be missing, avoid errors by checking:

 title_elem = book.find('title')
title = title_elem.text if title_elem is not None else "Unknown"

Or use a default:

 title = book.findtext('title', default='No Title')

4. Search with XPath-Like Expressions

ElementTree supports basic XPath expressions for deeper searches.

 # Find all titles under any book
titles = root.findall('.//title')

# Find books with a specific attribute
special_books = root.findall('.//book[@id="1"]')

# Find any element with attribute 'id'
elements_with_id = root.findall('.//*[@id]')

? Only a subset of XPath is supported, but it's enough for most use cases.

5. Modify and Write Back to File

You can also edit the XML and save it.

 # Add a new book
new_book = ET.SubElement(root, 'book', attrib={'id': '3'})
ET.SubElement(new_book, 'title').text = 'Web Scraping with Python'
ET.SubElement(new_book, 'author').text = 'Jane Cole'

# Modify an existing element
for book in root.findall('book'):
    if book.find('author').text == 'Anna Lee':
        book.find('author').text = 'A. Lee'

# Write changes to a new file
tree.write('updated_data.xml', encoding='utf-8', xml_declaration=True)

? Always call .write() on the tree , not the root .

Final Tips

• Handle malformed XML with try-except:

   try:
      tree = ET.parse('data.xml')
  except ET.ParseError as e:
      print(f"XML parsing error: {e}")

• Namespaces? Use {namespace}tagname in searches if needed.

• For large files, consider iterparse() to stream and save memory.

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Basically, ElementTree gives you a clean, independent way to work with XML without external dependencies. It's not as powerful as full XPath engines, but for most tasks — reading config files, processing feeds, or simple data exchange — it's more than enough.

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