python - Reading and writing an array in a file using C functions in cython -
    i instantiating class in cython . want declare 1 of instance array of float  values once computing given function , save in binary file using c  functions. further call of class if input file exist, instance declared reading array file otherwise compute again.   import numpy np cimport numpy np cimport cython  libc.stdio cimport file, fopen, fwrite, fscanf, fclose, fseek, seek_end, ftell, stdout, stderr cdef extern "math.h":     double exp(double) nogil     double log(double) nogil  cdef class hit(object):     cdef public double[::1] zs, da     cdef char* path      def __cinit__(self, zs=none, path=none):         if path none:            raise valueerror("could not find path file contains table of distances")         else:            self.path=path         if zs none:            raise valueerror("you must give array contains steps!")         self.zs=zs         cdef py_ssize_t i, n         n=len(self.zs)         cdef file *ptr_fr         cdef file *ptr_...