The ElementTree type is a simple but flexible container object, designed
to store hierarchical data structures, such as simplified XML infosets,
in memory. The element type can be described as a cross between a Python
list and a Python dictionary.

The cElementTree module is a C implementation of the ElementTree API. On
typical documents, it's 15-20 times faster than the Python version of
ElementTree, and uses 2-5 times less memory.