Function PyArray_FromArray

numpy/core/src/multiarray/ctors.c:1840–1986

NUMPY_API * steals reference to newtype --- acc. NULL */

 * steals reference to newtype --- acc. NULL
 */
NPY_NO_EXPORT PyObject *
PyArray_FromArray(PyArrayObject *arr, PyArray_Descr *newtype, int flags)
{

    PyArrayObject *ret = NULL;
    int copy = 0;
    int arrflags;
    PyArray_Descr *oldtype;
    NPY_CASTING casting = NPY_SAFE_CASTING;

    oldtype = PyArray_DESCR(arr);
    if (newtype == NULL) {
        /*
         * Check if object is of array with Null newtype.
         * If so return it directly instead of checking for casting.
         */
        if (flags == 0) {
            Py_INCREF(arr);
            return (PyObject *)arr;
        }
        newtype = oldtype;
        Py_INCREF(oldtype);
    }
    else if (PyDataType_ISUNSIZED(newtype)) {
        PyArray_DESCR_REPLACE(newtype);
        if (newtype == NULL) {
            return NULL;
        }
        newtype->elsize = oldtype->elsize;
    }

    /* If the casting if forced, use the 'unsafe' casting rule */
    if (flags & NPY_ARRAY_FORCECAST) {
        casting = NPY_UNSAFE_CASTING;
    }

    /* Raise an error if the casting rule isn't followed */
    if (!PyArray_CanCastArrayTo(arr, newtype, casting)) {
        PyErr_Clear();
        npy_set_invalid_cast_error(
                PyArray_DESCR(arr), newtype, casting, PyArray_NDIM(arr) == 0);
        Py_DECREF(newtype);
        return NULL;
    }

    arrflags = PyArray_FLAGS(arr);
           /* If a guaranteed copy was requested */
    copy = (flags & NPY_ARRAY_ENSURECOPY) ||
           /* If C contiguous was requested, and arr is not */
           ((flags & NPY_ARRAY_C_CONTIGUOUS) &&
                   (!(arrflags & NPY_ARRAY_C_CONTIGUOUS))) ||
           /* If an aligned array was requested, and arr is not */
           ((flags & NPY_ARRAY_ALIGNED) &&
                   (!(arrflags & NPY_ARRAY_ALIGNED))) ||
           /* If a Fortran contiguous array was requested, and arr is not */
           ((flags & NPY_ARRAY_F_CONTIGUOUS) &&
                   (!(arrflags & NPY_ARRAY_F_CONTIGUOUS))) ||
           /* If a writeable array was requested, and arr is not */