Remainder of numbers in python

Question

Can anyone answer me why?!
-20%6 = 4
Why not -2 ?
(6*-3)+(-2)=-20
But in here in python it equals 4 ?!?! 🤔🤔🤔🤔

Answer 1

I never noticed this in python.
I looked on internet and find this:
https://stackoverflow.com/questions/3883004/the-modulo-operation-on-negative-numbers-in-python

Answer 2

Thank you PanicS for your great answer, but isn't it a serious bug?
It's not normal at all!

Answer 3

Manav Roy I checked java!
Also in jave it prints -2 😐
but in python it shows 4 !

Answer 4

Oma Falk What does Guido mean?
Guido van Rossum, the creator of python?

Answer 5

In school they teached us that the modulo operation gives strictly a positive integer, so that's why it gives 4 and -2. I guess python just follows the rules of maths.

Answer 6

ohhhh there are many bugs in programming eg:
a = a+1
Implement modulo in the most useful manner.

Guido and the fathers of C-languages and the fathers of Java had different opinions... that's all.

Guidos idea was that the modulo 6 repeats every 6 numbers.
10%6 == 4%6 == -2%6 ==-8%6 == -14%6 == -20% 6 ==4.
Seems logical to me.

Answer 7

I just find answer on internet, I don't know much python i code mostly with javascript.

It can make bugs in your code if you dont know that this is diferent than in other language, but I don't think this is bug in language itself, this can be useful in some specific situation.

Answer 8

BTW... -2 and 4 are congruent with Respekt to mod 6

Answer 9

I asked something along the same line sometime ago

https://www.sololearn.com/discuss/3065059/?ref=app