How to round up to 32 using the math module (Python 3,)

Question

Is it possible to round upwords using the built-in math module? I know that you can use math.floor() to round down, but is there a way to round up? Currently, I use this to round:

def roundTo32(x, base=32):
    return int(base * round(float(x) / base))

but that doesn't always round up.

possible duplicate of [Round to 5(or other number) in python](http://stackoverflow.com/questions/2272149/round-to-5or-other-number-in-python) — blueberryfields, Jan 13 '14 at 20:52
@blueberryfields: That post uses the exact method the OP is using, to round to the nearest multiple. That means `15` is rounded *down*, not up. — Martijn Pieters, Jan 13 '14 at 20:54

score 3 · Accepted Answer · answered Jan 13 '14 at 20:50

Use math.ceil() to round float values up:

import math

def roundTo32(x, base=32):
    return int(base * math.ceil(float(x) / base))

Demo:

>>> import math
>>> def roundTo32(x, base=32):
...     return int(base * math.ceil(float(x) / base))
... 
>>> roundTo32(15)
32
>>> roundTo32(33)
64

score 2 · Answer 2 · answered Apr 05 '17 at 16:19

2

If you want to only use integers, you can also do:

def roundTo32(x):
    return (x + 31) & ~31

the part & ~31 is possible because 32 is a power of two.

answered Apr 05 '17 at 16:19

user666412

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How to round up to 32 using the math module (Python 3,)

2 Answers2