1、math向下取整，向上取整：math.ceil(),math.floor()：
2、round四舍五入算法，以及 round(x.5)奇进偶不进：
"""@Project : For_Python_Pro@File : 四舍五入之round，math.py@Author : Administrator@Time : 2022/12/24 12:56@Product : PyCharm"""import math# math四舍五入算法：# 向上取整：print('')print(math.ceil(3.1415926)) # 4print(math.ceil(3.1415926100)/100) # 3.15# 向下取整：print(math.floor(3.1415926)) # 3print(math.floor(3.1415926100)/100) # 3.14# 返回整数部分 math.trunc()：相称于向下取整 math.ceil()print('====================')print(math.trunc(3.1415926)) # 3print(math.trunc(3.1415926100)/100) # 3.14# 取绝对值 math.fabs()，得到浮点数，即小数：print('--------------------')print(math.fabs(-3.14)) # 3.14print(math.fabs(-3)) # 3.0print(math.fabs(-4)) # 4.0print(math.fabs(4)) # 4.0print('////////////////////')print(math.fmod(5,3)) # 2.0 # 取余，浮点数，即小数：# round四舍五入算法：# 范式一：print(round(3,2)) # 3print(round(3.1415926,0)) # 3.0print(round(3.1415926,1)) # 3.1print(round(3.1415926,2)) # 3.14print(round(3.1415926,3)) # 3.142print(round(3.1415926,4)) # 3.1416# 范式二：# x.5，x为奇数，进位；x为偶数，不进位：print(round(1.4)) # 1print(round(1.5)) # 2 # x为奇数，进位；print(round(1.6)) # 2 # x为奇数，进位；print(round(2.5)) # 2 # x为偶数，不进位：print(round(3.4)) # 3print(round(3.5)) # 4 # x为奇数，进位；print(round(4.5)) # 4 # x为偶数，不进位：# round(X)和round(X,0)，差异便是有一位为0的小数位print(round(3.5,0)) # 4 # x为奇数，进位；print(round(4.5,0)) # 4 x为偶数，不进位：
