详解如何利用Cython为Python代码加速

import numpy as np 
cimport numpy as np 
cimport cython


DTYPE = np.float
ctypedef np.float_t DTYPE_t

def update_state(np.ndarray[DTYPE_t, ndim=2] cells):
  return update_state_c(cells)

@cython.boundscheck(False)
@cython.wraparound(False)
cdef np.ndarray[DTYPE_t, ndim=2] update_state_c(np.ndarray[DTYPE_t, ndim=2] cells):
  """更新一次状态"""
  cdef unsigned int i
  cdef unsigned int j

  cdef np.ndarray[DTYPE_t, ndim=2] buf = np.zeros((cells.shape[0], cells.shape[1]), dtype=DTYPE)
  cdef DTYPE_t neighbor_num
  for i in range(1, cells.shape[0] - 1):
    for j in range(1, cells.shape[0] - 1):
      # 计算该细胞周围的存活细胞数
      
      neighbor_num = cells[i, j-1] + cells[i, j+1] + cells[i+1, j] + cells[i-1, j] +\
              cells[i-1, j-1] + cells[i-1, j+1] +\
              cells[i+1, j-1] + cells[i+1, j+1]
      
      if neighbor_num == 3:
        buf[i, j] = 1
      elif neighbor_num == 2:
        buf[i, j] = cells[i, j]
      else:
        buf[i, j] = 0
  return buf

import numpy as np
from distutils.core import setup
from Cython.Build import cythonize

setup(
  name="Cython Update State",
  ext_modules=cythonize("update.pyx"),
  include_dirs=[np.get_include()]
)

def update_state(self):
  """更新一次状态"""
  self.cells = cupdate.update_state(self.cells)
  self.timer += 1

def test_time():
  import time
  game = GameOfLife(cells_shape=(60, 60))
  t1 = time.time()
  for _ in range(300):
    game.update_state()
  t2 = time.time()
  print("Cython Use Time:", t2 - t1)
  del game
  game = GameOfLife(cells_shape=(60, 60))
  t1 = time.time()
  for _ in range(300):
    game.update_state_py()
  t2 = time.time()
  print("Native Python Use Time:", t2 - t1)