74. Working with XML using xml.etree

Here are 10 Python code snippets demonstrating how to work with XML documents using the xml.etree.ElementTree module for parsing and creating XML files.

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1. Parsing an XML String

This example shows how to parse an XML string into an ElementTree object and print the tag names.

import xml.etree.ElementTree as ET

xml_data = '''<root>
                    <child1>data1</child1>
                    <child2>data2</child2>
                </root>'''

# Parse XML string
root = ET.fromstring(xml_data)

# Access and print tag names
for child in root:
    print(child.tag, child.text)

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2. Parsing an XML File

This example demonstrates how to parse an XML file using ElementTree.parse().

import xml.etree.ElementTree as ET

# Parse XML file
tree = ET.parse('sample.xml')
root = tree.getroot()

# Access and print tags
for child in root:
    print(child.tag, child.text)

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3. Creating an XML Document

This example shows how to create an XML document using ElementTree.

import xml.etree.ElementTree as ET

# Create root element
root = ET.Element("root")

# Create child elements
child1 = ET.SubElement(root, "child1")
child1.text = "data1"
child2 = ET.SubElement(root, "child2")
child2.text = "data2"

# Generate XML string
tree = ET.ElementTree(root)
tree.write("output.xml")

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4. Finding Elements with XPath

This snippet demonstrates how to find elements using XPath expressions.

import xml.etree.ElementTree as ET

xml_data = '''<root>
                    <child1>data1</child1>
                    <child2>data2</child2>
                    <child1>data3</child1>
                </root>'''

# Parse XML string
root = ET.fromstring(xml_data)

# Find all elements with tag 'child1'
for child in root.findall('child1'):
    print(child.tag, child.text)

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5. Modifying XML Elements

This example demonstrates how to modify an XML element's attributes and text content.

import xml.etree.ElementTree as ET

xml_data = '''<root>
                    <child1>data1</child1>
                    <child2>data2</child2>
                </root>'''

# Parse XML string
root = ET.fromstring(xml_data)

# Modify the text of 'child1'
child1 = root.find('child1')
child1.text = "new_data1"

# Generate modified XML
tree = ET.ElementTree(root)
tree.write("modified_output.xml")

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6. Setting Element Attributes

This example demonstrates how to add and modify attributes in XML elements.

import xml.etree.ElementTree as ET

# Create root element
root = ET.Element("root")

# Create child element with an attribute
child = ET.SubElement(root, "child", name="child1")
child.text = "data"

# Print XML
tree = ET.ElementTree(root)
tree.write("output_with_attributes.xml")

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7. Iterating Over XML Elements with Attributes

Here we show how to iterate over XML elements and access their attributes.

import xml.etree.ElementTree as ET

xml_data = '''<root>
                    <child name="child1">data1</child>
                    <child name="child2">data2</child>
                </root>'''

# Parse XML string
root = ET.fromstring(xml_data)

# Iterate over children and access their attributes
for child in root:
    print(child.tag, child.attrib['name'], child.text)

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8. Converting XML Document to String

This example demonstrates how to convert an ElementTree object back to a string.

import xml.etree.ElementTree as ET

# Create root element
root = ET.Element("root")
child = ET.SubElement(root, "child")
child.text = "data"

# Convert to string
xml_str = ET.tostring(root, encoding='unicode')
print(xml_str)

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9. Pretty Printing an XML File

To make XML output more readable, you can use minidom for pretty printing.

import xml.etree.ElementTree as ET
from xml.dom import minidom

# Create root element
root = ET.Element("root")
child = ET.SubElement(root, "child")
child.text = "data"

# Convert to string
xml_str = ET.tostring(root, encoding='utf-8')

# Pretty print XML
xml_str = minidom.parseString(xml_str).toprettyxml(indent="  ")
print(xml_str)

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10. Removing an Element from XML

This snippet demonstrates how to remove an element from an XML document.

import xml.etree.ElementTree as ET

xml_data = '''<root>
                    <child1>data1</child1>
                    <child2>data2</child2>
                </root>'''

# Parse XML string
root = ET.fromstring(xml_data)

# Find and remove 'child1' element
child1 = root.find('child1')
root.remove(child1)

# Print modified XML
tree = ET.ElementTree(root)
tree.write("output_without_child1.xml")

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These code snippets illustrate how to work with XML data using the xml.etree.ElementTree module. You can use this module to parse, modify, create, and write XML documents efficiently in Python.