round

>>> round(3.400),round(3.5000),round(3.600)
(3, 4, 4)
>>> round(2.400),round(2.5000),round(2.600)
(2, 2, 3)
>>> round(2.400),round(2.5001),round(2.600)
(2, 3, 3)
>>>

　　4舍6入，5取偶（靠近的偶数）

 

>>> round(-2.400),round(-2.5001),round(-2.600)
(-2, -3, -3)
>>> round(-2.400),round(-2.5000),round(-2.6)
(-2, -2, -3)
>>> round(-3.400),round(-3.5000),round(-3.600)
(-3, -4, -4)
>>>