Python开根号性能对比：math.sqrt、pow与cmath实测

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

import math
n = int(input('数字:'))
x = math.sqrt(n)
print(x)
print(type(x)) #开根号后的类型为float

n = int(input('数字:'))
x = pow(n,0.5)
print(x)
print(type(x)) #开根号后的类型为float

import cmath
n = int(input('数字: '))
x = cmath.sqrt(n)
print(x)
print(type(x)) #类型为complex