为什么会这样?

但赛顿成了救世主

下面的纯python版本借用了Glenn Maynard的答案(没有打印)

基于此,cython版本非常简单,对于一个新的python程序员来说已经足够简单了:

def main():

cdef int i = 0

cdef int a = 0

while i < 6553500:

i += 1

if i != 6553500:

a = i

else:

pass # print "0"

return a

if __name__ == "__main__":

print main()

在我的电脑上,python版本需要2.5s,cython版本需要5.5ms:

In [1]: import pyximport

In [2]: pyximport.install()

In [3]: import spam # pure python version

In [4]: timeit spam.main()

1 loops, best of 3: 2.41 s per loop

In [5]: import eggs # cython version

In [6]: timeit eggs.main()

100 loops, best of 3: 5.51 ms per loop

更新:正如Glenn Maynard在评论中指出的,而i

我测试xrange的实现。

spam.py和Glenn Maynard的verison是一样的。py的代码是:

def main():

for i in xrange(6553500):

pass

a = i

return a

if __name__ == "__main__":

print main()

~/code/note$ time python2.7 spam.py # Glenn Maynard's while version

6553499

real 0m2.128s

user 0m2.080s

sys 0m0.044s

:~/code/note$ time python2.7 foo.py # xrange version, as Glenn Maynard point out in comment

6553499

real 0m0.618s

user 0m0.604s