Best way to create a class dynamically on the fly?

[Robert Oschler]

What is the best way to create a Python class dynamically at runtime?  A
sample or doc would be great.  I'm a veteran C++ programmer so this concept
is very alien to me as you can imagine (dynamically created classes).  An
example that would show the creation of a descendant (sub-class), and a
another example showing the creation of an ancestor class would be perfect.

thx