循环的优化

1.尽量减少循环内部不必要的计算

2.嵌套循环中，尽量较少内层循环的计算，尽可能向外提

3.局部变量查询较快，尽量使用局部变量

 

#!/usr/bin/env python
#-*- coding:utf-8 -*-
import time

start=time.time()
for i in range(1000):
    result=[]
    for m in range(10000):
        result.append(i*1000+m*100)


end=time.time()
print("耗时: {0}",format((end-start)))


start2=time.time()
for i in range(1000):
    result=[]
    c=i*1000
    for m in range(10000):
        result.append(c+m*100)

end2=time.time()
print("耗时: {0}".format((end2-start2)))