Ceiling是向上取整
floor是向下取整
Round是四舍五入的

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ceil

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描述

ceil() 函数返回数字的上入整数

ceil()：将小数部分一律向整数部分进位。

#!/usr/bin/python
import math   # This will import math moduleprint "math.ceil(-45.17) : ", math.ceil(-45.17)
print "math.ceil(100.12) : ", math.ceil(100.12)
print "math.ceil(100.72) : ", math.ceil(100.72)
print "math.ceil(119L) : ", math.ceil(119L)
print "math.ceil(math.pi) : ", math.ceil(math.pi)

输出结果为：

math.ceil(-45.17) :  -45.0
math.ceil(100.12) :  101.0
math.ceil(100.72) :  101.0
math.ceil(119L) :  119.0
math.ceil(math.pi) : 4.0

#向上取整
print "math.ceil---"
print "math.ceil(2.3) => ", math.ceil(2.3)
print "math.ceil(2.6) => ", math.ceil(2.6)

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floor

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floor()：一律舍去，仅保留整数

math.floor(12.2)// 返回12
math.floor(12.7)//返回12
math.floor(12.0)//返回12

#向下取整
print "\nmath.floor---"
print "math.floor(2.3) => ", math.floor(2.3)
print "math.floor(2.6) => ", math.floor(2.6)

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round

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round()：进行四舍五入

math.round(12.2)// 返回12
math.round(12.7)//返回13
math.round(12.0)//返回12 

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#encoding:utf-8
import math#这三个的返回结果都是浮点型
print "\n\nNOTE:every result is type of float"
print "math.ceil(2) => ", math.ceil(2)
print "math.floor(2) => ", math.floor(2)
print "round(2) => ", round(2)