How to Use the Python lxml Library

09/12/2021

Contents

In this article, you will learn how to use the Python lxml library.

Python lxml Library

The Python lxml library is a powerful library for processing XML and HTML documents. Here’s a brief guide on how to use lxml:

Installation:

You can install lxml using pip by running the following command:

pip install lxml
Parsing XML or HTML Documents:

To parse an XML or HTML document using lxml, you need to create an Element object. Here’s an example of how to parse an XML document:

from lxml import etree

xml = "hello world"
root = etree.fromstring(xml)
Navigating the Document:

Once you have an Element object, you can navigate the document using various methods. Here are some examples:

# Get the root element
root = tree.getroot()

# Get the child elements of the root
children = root.getchildren()

# Get the value of an element
value = root.find("element").text

# Get all elements with a specific tag name
elements = root.findall("element")
Modifying the Document:

You can modify the XML or HTML document using various methods. Here are some examples:

# Add a new element to the document
new_element = etree.Element("new_element")
root.append(new_element)

# Remove an element from the document
element_to_remove = root.find("element")
root.remove(element_to_remove)

# Update the value of an element
element_to_update = root.find("element")
element_to_update.text = "new value"
Outputting the Document:

Once you’ve made changes to the XML or HTML document, you can output it as a string or write it to a file. Here are some examples:

# Output the XML as a string
xml_string = etree.tostring(root)

# Write the XML to a file
with open("output.xml", "wb") as f:
    f.write(etree.tostring(root))

That’s a brief introduction to using the lxml library in Python. There are many more features and methods available, so be sure to consult the documentation for more information.