%load_ext cythonmagic

%%cython
from libc.stdlib cimport malloc, free
cimport numpy as np
import numpy as np
from cython cimport view

N = 10000

def memview_malloc():
    cdef int * m = <int *>malloc(N * sizeof(int))
    cdef int[::1] b = <int[:N]>m
    free(<void *>m)

def memview_ndarray():
    cdef int[::1] b = np.empty(N, dtype=np.int32)
    
def memview_cyarray():
    cdef int[::1] b = view.array(shape=(N,), itemsize=sizeof(int), format="i")

%timeit memview_malloc()

%timeit memview_ndarray()

%timeit memview_cyarray()