Mutable variants of tuple (mutabletuple) and collections.namedtuple (recordclass), which support assignments and more memory saving variants (dataobject, structclass, litelist, ...).
Package frozentype provide some frozen python types (frozendict (C based) and frozenmap (Cython based))
Package frozenmap provide frozendict (C based) and frozenmap (Cython based)
Python library for AXON
Cython based buffer for arrays and typed memoryviews.