py_builtin              Retrieve a Python built-in function or
                        exception constructor by name
py_class                Python class system: C3 MRO, 'super()',
                        descriptors, and 'with' context managers
py_eq                   Python comparison, identity, and membership
                        operators
py_exception            Construct, raise, and catch Python exceptions
py_int                  Python 'int()' constructor and exact integer /
                        operator semantics
py_iter                 Python iteration protocol ('iter', 'next'),
                        generators, and 'range'
py_len                  Python 'len()' and container constructors
                        ('list', 'tuple', 'dict', 'set')
py_ndarray              Create a Python-compatible 'ndarray' backed by
                        an R vector/matrix/array
py_none                 Python 'None', 'Ellipsis', and truthiness
                        helpers
py_random_generator     Bit-exact CPython 'random.Random' generator and
                        module-level 'py_random'
py_slice                Python 'slice()' and 0-based subscript helpers
py_split_varargs        Runtime helpers for transpiled *args/**kwargs,
                        'assert', and signals
py_stdlib               Retrieve a Python standard-library module
                        implemented in 'pyrt'
py_str                  Python 'str()', 'repr()', 'ascii()',
                        'format()', and 'str' methods
