Extracting Attributes and Text from XML Elements

From Repeated XML to Python Data

When XML contains several similar structures, such as multiple user elements, extracting only one node is not enough. The useful pattern is to find every matching node, receive those nodes as a Python list, and process the list with a for loop. This avoids writing separate extraction code for each user or record.

import xml.etree.ElementTree as ET

xml_data = """<users>
  <user x="2">
    <id>001</id>
    <name>Chuck</name>
  </user>
  <user x="7">
    <id>009</id>
    <name>Brent</name>
  </user>
</users>"""

root = ET.fromstring(xml_data)
lst = root.findall("user")

Selecting Matching Elements

findall retrieves a Python list containing all XML nodes that match the path supplied to it. In the example, root.findall("user") searches the parsed XML tree below the users container for user elements. The path determines which elements are selected from the document hierarchy.

2

Walking Through the List

After findall returns, a for loop visits each Element in the list one at a time. The loop variable represents the current XML node. During the first iteration, item represents the first user. During the second iteration, item represents the second user. The loop body runs once for each item and stops after all list items have been processed.

for item in lst: print(item.find("name").text) print(item.get("x"))

Chuck
2
Brent
7

Reading Child Text and Attributes

XML data inside a matched node can appear as child-element text or as an attribute on the element itself. Use item.find("name").text to locate the name child element and read the text between its tags. Use item.get("x") to retrieve the x attribute directly from the current user element. Attributes belong to the element being processed, so find is not needed before get.

Tracing One Complete Pass

Diagnosing Empty or Failing Loops

When iteration does not produce the expected result, inspect findall before changing the loop. First check the list length and inspect the first item. If len(lst) is 0, the path may be wrong or the XML structure may not match the expected structure. If the list length is correct but extraction fails inside the loop, inspect each item and verify the child-element and attribute names exactly. XML names are case-sensitive.

• Treating the result of findall as one XML node instead of a list.

  findall returns a Python list containing matching Element objects. The individual Element is available inside the for loop through its loop variable.

  Fix: Loop over the list and call find or get on the current item.

• Assuming an empty list means the loop is broken.

  A zero-length list means no elements matched the supplied path, so there is no item for the loop to process.

  Fix: Check the path and compare it with the XML hierarchy.

• Using the wrong child-element or attribute name.

  XML is case-sensitive, so names must match exactly.

  Fix: Inspect the current item and verify the child and attribute names before extracting.

Practice the Extraction Pattern

1. Parse the XML into a tree.
2. Call findall with the path for the repeating elements.
3. Check the returned list length and inspect an item if needed.
4. Use a for loop to bind each Element to the loop variable.
5. Use find followed by text for child-element content.
6. Use get for an attribute on the current Element.

Key Takeaways

1. findall returns a Python list of every XML Element matching a path.
2. A for loop visits the returned Elements one at a time, with the loop variable holding the current node.
3. Use find(child_name).text to read text from a child element.
4. Use get(attribute_name) to read an attribute from the current Element.
5. When extraction fails, check the list length, inspect an item, and verify names and paths exactly.