Create NumPy array using data from a C pointer

np_c_data.pyx

cimport numpy as cnp
cimport stdlib

cnp.import_array()

cdef class _dealloc_obj:

    cdef void *_data

    def __cinit__(self):
        self._data = NULL

    def __dealloc__(self):
        if self._data:
            stdlib.free(self._data)


cdef cnp.ndarray np_from_c_data(void *data, int nd, npy_intp *dims, dtype_enum):
    if data == NULL:
        raise MemoryError()
    if nd <= 0:
        raise ValueError('nd must be >= 0, got %d' % nd)
    arr = cnp.PyArray_SimpleNewFromData(nd, dims, dtype_enum, data)
    dobj = _dealloc_obj()
    dobj.ptr = data
    cnp.set_array_base(arr, dobj)
    return arr