Base classes of all of these are provided, but in most cases it is easiest to inherit from .DOM is a very-high-level tree-based representation of an XML document.You can always add any modules that are not included, or any new versions of included modules, later (and many of the modules that are not included themselves rely on services provided by the Py XML distribution).
Many readers will be most familiar with SGML via one particular document type, HTML.
This package contains many of the modules discussed in this article, some "getting started" documentation, some demonstration code, and whatever else the XML-SIG might decide to throw into the distribution.
A given package may not always contain the "bleeding edge" version of each individual module or tool, but downloading the Py XML distribution is a good place to start.
The familiar "read some lines and compare them to some regular expressions" style of text processing is generally not well-suited to adequately parsing and processing XML.
Python, fortunately (and more so than most other languages), has both straightforward ways of dealing with complex data structures (usually with classes and attributes), and a range of XML-related modules to aid in parsing, processing, and generating XML.