Cython (cdef classes)

如果外部要存取成員，記得成員要宣告為public, e.g.

from sin_of_square cimport Function

cdef class WaveFunction(Function):

    # Not available in Python-space:
    cdef double offset

    # Available in Python-space:
    cdef public double freq

    # Available in Python-space, but only for reading:
    cdef readonly double scale

    # Available in Python-space:
    @property
    def period(self):
        return 1.0 / self.freq

    @period.setter
    def period(self, value):
        self.freq = 1.0 / value