Benefits of xml.dom.minidom?

[Stefan Behnel]

John Gordon, 20.10.2011 19:46:
> I recently inherited some code that uses xml.dom.minidom to build a large
> XML document, and I noticed that it is quite slow and uses a ton of memory.
>
> I converted the same code to use lxml.etree and it is much faster and
> uses not nearly so much memory.
>
> Why is minidom so hungry for resources?  What is it doing with all that
> memory and CPU?

Not much. It's memory hungry because it builds a tree from rather heavy XML 
objects and is neither optimised for speed nor for a low memory footprint. 
Its main purpose is to be (mostly) W3C DOM compatible. It's also been in 
the standard library for quite a bit longer than ElementTree, and predates 
lxml by years. That's the most likely reason why your original script was 
written using minidom.

In a way, it's unfair to compare minidom with lxml.etree (or cElementTree, 
for that purpose), as the latter two were specifically designed for high 
performance and a much simpler API.

Stefan