An ndpointer instance is used to describe an ndarray in restypes and argtypes specifications. This approach is more flexible than using, for example, POINTER(c_double), since several restrictions can be specified, which are verified upon calling the ctypes function. These include data type, number of dimensions, shape and flags. If a given array does not satisfy the specified restrictions, a TypeError is raised.
dtype : data-type, optional
ndim : int, optional
shape : tuple of ints, optional
flags : string or tuple of strings
>>> clib.somefunc.argtypes = [np.ctypeslib.ndpointer(dtype=float64, ... ndim=1, ... flags='C_CONTIGUOUS')] >>> clib.somefunc(np.array([1, 2, 3], dtype=np.float64))