Quick Start¶

This guide will help you get started with pygixml quickly.

Basic Usage¶

Parsing XML¶

import pygixml

# Parse from string
xml_string = '''
<library>
    <book id="1">
        <title>The Great Gatsby</title>
        <author>F. Scott Fitzgerald</author>
        <year>1925</year>
    </book>
</library>
'''
doc = pygixml.parse_string(xml_string)

# Parse from file
doc = pygixml.parse_file("data.xml")

Navigating XML¶

# Get root element
root = doc.first_child()
print(f"Root name: {root.name()}")  # Output: library

# Access children
book = root.first_child()
print(f"Book name: {book.name()}")  # Output: book

# Get specific child by name
title = book.child("title")
print(f"Title: {title.child_value()}")  # Output: The Great Gatsby

# Iterate through children
current = root.first_child()
while current:
    print(f"Node: {current.name()}")
    current = current.next_sibling()

Working with Attributes¶

# Get attribute
book_id = book.attribute("id")
print(f"Book ID: {book_id.value()}")  # Output: 1

# Iterate through attributes
attr = book.first_attribute()
while attr:
    print(f"Attribute: {attr.name()} = {attr.value()}")
    attr = attr.next_attribute()

Creating and Modifying XML¶

Creating New Documents¶

import pygixml

# Create new document
doc = pygixml.XMLDocument()

# Add root element
root = doc.append_child("library")

# Add child elements
book = root.append_child("book")
book.set_attribute("id", "1")

title = book.append_child("title")
title.set_value("The Great Gatsby")

author = book.append_child("author")
author.set_value("F. Scott Fitzgerald")

# Save to file
doc.save_file("output.xml")

Modifying Existing XML¶

# Load existing XML
doc = pygixml.parse_string(xml_string)
root = doc.first_child()

# Modify values
book = root.first_child()
book.child("title").set_value("New Title")

# Add new elements
price = book.append_child("price")
price.set_value("12.99")

# Remove elements
year = book.child("year")
book.remove_child(year)

XPath Queries¶

Basic XPath Usage¶

# Select all books
books = root.select_nodes("book")
print(f"Found {len(books)} books")

# Select specific book by ID
book1 = root.select_node("book[@id='1']")
if book1:
    print(f"Book 1 title: {book1.node().child('title').child_value()}")

# Select books by year
old_books = root.select_nodes("book[year < 1950]")
print(f"Found {len(old_books)} old books")

Advanced XPath¶

# Using XPathQuery for repeated queries
query = pygixml.XPathQuery("book[price > 10]")
expensive_books = query.evaluate_node_set(root)

# XPath evaluations
has_books = pygixml.XPathQuery("book").evaluate_boolean(root)
avg_price = pygixml.XPathQuery("sum(book/price) div count(book)").evaluate_number(root)
first_title = pygixml.XPathQuery("book[1]/title").evaluate_string(root)

Error Handling¶

try:
    doc = pygixml.parse_string(invalid_xml)
except ValueError as e:
    print(f"Failed to parse XML: {e}")

try:
    doc.save_file("/invalid/path/file.xml")
except Exception as e:
    print(f"Failed to save file: {e}")

Next Steps¶

Learn about XPath capabilities
Explore API reference
Check out examples
Read about performance