frozen.pyx

from cpython.object cimport descrgetfunc, Py_TYPE


cdef class FrozenSlotDescriptor(object):
    """
    Wraps the normal Python slot descriptor, disabling write access.
    """
    cdef descrgetfunc get
    cdef object descriptor
    def __cinit__(self, orig):
        self.descriptor = orig
        self.get = Py_TYPE(orig).tp_descr_get

    def __get__(self, obj, type):
        return self.get(self.descriptor, obj, type)

    def __set__(self, obj, value):
        raise AttributeError('This attribute is frozen.')

    def __delete__(self, obj):
        raise AttributeError('This attribute is frozen.')