Modulo operator in Python

python python-3.x operators
KodeWarrior picture KodeWarrior · Oct 6, 2012 · Viewed 382.1k times · Source

What does modulo in the following piece of code do?

from math import *
3.14 % 2 * pi

How do we calculate modulo on a floating point number?

Answer

Blender picture Blender · Oct 6, 2012

When you have the expression:

a % b = c

It really means there exists an integer n that makes c as small as possible, but non-negative.

a - n*b = c

By hand, you can just subtract 2 (or add 2 if your number is negative) over and over until the end result is the smallest positive number possible:

  3.14 % 2
= 3.14 - 1 * 2
= 1.14

Also, 3.14 % 2 * pi is interpreted as (3.14 % 2) * pi. I'm not sure if you meant to write 3.14 % (2 * pi) (in either case, the algorithm is the same. Just subtract/add until the number is as small as possible).

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