python不同开根号速度对比

import time

import math

import numpy as np

def timeit1():

    s = time.time()

    for i in range(750000):

        z=i**.5

    print ("Took %f seconds" % (time.time() - s))

def timeit2(arg=math.sqrt):

    s = time.time()

    for i in range(750000):

        z=arg(i)

    print ("Took %f seconds" % (time.time() - s))

def timeit3(arg=np.sqrt):

    s = time.time()

    for i in range(750000):

        z=arg(i)

    print ("Took %f seconds" % (time.time() - s))

def timeit4():

    s = time.time()

    for i in range(750000):

        z=math.pow(i,.5)

    print ("Took %f seconds" % (time.time() - s))

timeit1()

timeit2()

timeit3()

timeit4()

Took 0.152364 seconds

Took 0.061580 seconds

Took 1.016529 seconds

Took 0.215403 seconds