from cffi import FFI
    import numpy as np

    s = '''
        typedef struct
        {
            int a;
            int b;
            float c;
            double d;
        } mystruct;
        '''
    ffi = FFI()
    ffi.cdef(s)

    m_arr = ffi.new("mystruct[2]")

    #create array and fill with dummy data
    for k in range(2):

        m = m_arr[k]

        m.a = k
        m.b = k + 1
        m.c = k + 2.0
        m.d = k + 3.0

    print(m_arr)

    # dtype for structured array in Numpy
    dt = np.dtype({'names': ('a', 'b', 'c', 'd'),
                   'formats': ('i4', 'i4', 'f4', 'f8'),
                   'offset': (ffi.offsetof('mystruct', 'a'),
                              ffi.offsetof('mystruct', 'b'),
                              ffi.offsetof('mystruct', 'c'),
                              ffi.offsetof('mystruct', 'd'),
                          )
                  }, align=True)
  
    # member size, 20 bytes
    print('size, manually', 4 + 4 + 4 + 8)

    # total size of struct, 24 bytes
    print('sizeof', ffi.sizeof(m_arr[0]))


    #reason is member padding in structs

    buf = ffi.buffer(m_arr)
    print(buf)

    x = np.frombuffer(buf, dtype=dt)
    print(x)