Python: Essential Reference, Third Edition

Defining New Python Types

One of the most advanced topics in extension building is defining new Python types in C/C++. Just as it is possible to add new functions to Python, one can add entirely new objects that behave similarly to the other built-in types, such as lists, tuples, and dictionaries.

The steps involved in adding a new type to Python are considerable and are not discussed further here. However, in practice, it rarely seems necessary to manually add a new type. For one, most of Python’s built-in types can be subclassed directly in Python. Therefore, if your only goal is to slightly modify one of the existing types, that can already be done without resorting to a C extension module. Second, a huge number of third-party extension modules ...