`numpy.ctypeslib:ndpointer`

source: /numpy/ctypeslib/_ctypeslib.py :238

Signature

   def     ndpointer (    dtype    =  None   ,    ndim    =  None   ,    shape    =  None   ,    flags    =  None     )

Summary

Array-checking restype/argtypes.

Extended Summary

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.

Parameters

dtype : data-type, optional

Array data-type.

ndim : int, optional

Number of array dimensions.

shape : tuple of ints, optional

Array shape.

flags : str or tuple of str

Array flags; may be one or more of:

C_CONTIGUOUS / C / CONTIGUOUS
F_CONTIGUOUS / F / FORTRAN
OWNDATA / O
WRITEABLE / W
ALIGNED / A
WRITEBACKIFCOPY / X

Returns

klass : ndpointer type object: A type object, which is an _ndtpr instance containing dtype, ndim, shape and flags information.

Raises

: TypeError: If a given array does not satisfy the specified restrictions.

Examples

clib.somefunc.argtypes = [np.ctypeslib.ndpointer(dtype=np.float64,
                                                 ndim=1,
                                                 flags='C_CONTIGUOUS')]
#doctest: +SKIP
clib.somefunc(np.array([1, 2, 3], dtype=np.float64))
#doctest: +SKIP

Aliases

numpy.ctypeslib.ndpointer