XML handling in Python - a new teaching example using etree

This is now an archive web site.
Some is still relevant as at October 2026 but some is purely of historic interest.

Lisa and I (Graham) are now fully retired from IT training.We have made many friends over 30 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Apache, Linux and Solaris/SunOS too. Our training notes are out of date, but with upward compatability some examples remain operational and relevant. You are welcome to make use of them "as seen", at your own risk. We now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We remain active, enjoying the times that we are retired but still healthy enough in mind and body to do things!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))

XML handling in Python - a new teaching example using etree (written 2015-12-09)

From the Python course just completed - a new example of XML handling, through the xml.etree.ElementTree module which was first available in Python 2.5.

  import xml.etree.ElementTree as etree

  try:

    tree = etree.parse(args.sourcefile[0])

  except Exception as e:

    print('FAILED to parse - reason %s' % e)

    exit(2)

An exception is thrown if the file cannot be opened, or if it can but contains badly formed XML, for example:

  munchkin:cambx grahamellis$ ./xmlparserdemo 6_context.xml 

  FAILED to parse - reason not well-formed (invalid token): line 3, column 1

Run with a properly formed and readable XML file, you can then iterate through the tree, and indeed do so recuresively if you wish:

  root = tree.getroot()

  for thing in root:

    print(thing)

    print(thing.attrib)

    print(thing.tag)

    print(thing.text)

    kids = thing.getchildren()

    print(kids)

    print("------------------")

Here's a sample of the results you may get (from a very short piece of XML in this case!)

  munchkin:cambx grahamellis$ ./xmlparserdemo -r 6_context.xml 

  <Element 'WatchedResource' at 0x10a037e10>

  {}

  WatchedResource

  WEB-INF/web.xml

  []

  ------------------

That's a single tag within the root, with no attributes (hence the empty dict) and no children (hence the empty list).

Complete program using this code [here] ... the program starts with an example of command line handling - the sample XML file I used is [here]. It also includes code to explore all elements of the tree ... Finally, the xml.etree.ElementTree module also includes tree searchimg and amendment methods.
(written 2015-12-09)

Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles

Y151 - Python & XML
  [2378] Handling XML in Perl - introduction and early examples - (2009-08-27)
  [2506] Good example of recursion in Python - analyse an RSS feed - (2009-11-18)
  [2555] Bookkeeping - (2009-12-29)
  [3082] XML handling in Python - SAX, DOM and XSLT examples - (2010-12-09)
  [4710] Searching a Json or XML structure for a specific key / value pair in Python - (2016-10-30)

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