Reading XML with Code

To use XML data, a program parses it: it reads the text and turns it into a tree of objects you can work with.

What is a Parser?

A parser reads XML text, checks that it is well-formed, and builds a tree in memory (the DOM, Document Object Model). Every major language has one built in.

Language	Built-in tool
JavaScript (browser)	`DOMParser`
Python	`xml.etree.ElementTree`
PHP	`SimpleXML`
C#	`System.Xml.Linq` (XDocument)
Java	`javax.xml.parsers`

JavaScript: DOMParser

Example

javascript

const text = `
<shop>
  <product><name>Galaxy A15</name><price>42000</price></product>
  <product><name>Fast Charger</name><price>2500</price></product>
</shop>`;

const doc = new DOMParser().parseFromString(text, "application/xml");

if (doc.querySelector("parsererror")) {
  console.log("The XML is not well-formed.");
} else {
  for (const p of doc.querySelectorAll("product")) {
    const name = p.querySelector("name").textContent;
    const price = Number(p.querySelector("price").textContent);
    console.log(`${name}: Rs ${price.toLocaleString("en-PK")}`);
  }
}

Output

Galaxy A15: Rs 42,000
Fast Charger: Rs 2,500

If the XML is broken, DOMParser does not throw an error. Instead, the result contains a <parsererror> element, so always check for it.

To load an XML file from a server, use fetch():

Example

javascript

const res = await fetch("/sitemap.xml");
const xml = new DOMParser().parseFromString(await res.text(), "application/xml");
console.log(xml.getElementsByTagName("loc").length + " pages in the sitemap");

Python: ElementTree

Example

python

import xml.etree.ElementTree as ET

text = """
<students>
  <student id="S01"><name>Ali Raza</name><marks>78</marks></student>
  <student id="S02"><name>Ayesha Khan</name><marks>91</marks></student>
  <student id="S03"><name>Bilal Ahmed</name><marks>55</marks></student>
</students>
"""

root = ET.fromstring(text)

for s in root.findall("student"):
    name = s.find("name").text
    marks = int(s.find("marks").text)
    print(s.get("id"), name, "Pass" if marks >= 60 else "Needs practice")

top = max(root.findall("student"), key=lambda s: int(s.find("marks").text))
print("Top student:", top.find("name").text)

Output

S01 Ali Raza Pass
S02 Ayesha Khan Pass
S03 Bilal Ahmed Needs practice
Top student: Ayesha Khan

For a file, use ET.parse("students.xml").getroot(). ElementTree also supports simple XPath, like root.findall(".//student[@id='S02']").

Creating XML with Python

Example

python

import xml.etree.ElementTree as ET

order = ET.Element("order", id="1045")
ET.SubElement(order, "customer").text = "Sana"
ET.SubElement(order, "total", currency="PKR").text = "3200"

ET.indent(order)
print(ET.tostring(order, encoding="unicode"))

Output

<order id="1045">
  <customer>Sana</customer>
  <total currency="PKR">3200</total>
</order>

Always build XML with a library like this instead of joining strings. The library escapes characters like & and < for you, so the result is always well-formed.

Real Uses: RSS and Sitemaps

An RSS feed lists the latest posts of a blog or news site. Apps and readers check it for new content:

Example

xml

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Workownix Blog</title>
    <link>https://example.com/blog</link>
    <item>
      <title>5 Tips for New Freelancers</title>
      <link>https://example.com/blog/freelance-tips</link>
      <pubDate>Thu, 15 Oct 2026 09:00:00 +0500</pubDate>
    </item>
  </channel>
</rss>

A sitemap (/sitemap.xml) tells search engines which pages your website has, as you saw in the namespaces lesson. Submitting it in Google Search Console helps your pages get found.

XML vs JSON

	XML	JSON
Looks like	Tags	Curly braces and keys
Size	Larger	Smaller
Attributes and namespaces	Yes	No
Schemas and validation	Strong (XSD)	JSON Schema
Common in	Documents, feeds, enterprise systems, office files	Web and mobile APIs

Most new web APIs use JSON, but XML is still the standard for sitemaps, RSS, SVG, office documents and many banking and government systems.

Exercise

In Python's ElementTree, which method gets the value of an attribute?

s.text("id")s.find("id")s.get("id")s.attr("id")