I want an explanation about the following expression(in description) which uses floor division, modulo, and comparison operators

Question

print((-9//4)==(-(9//4+1)) and (-9%4)==(4-9%4))
What is the output? Also, help me to understand it better.

Answer 1

// is python floor division which always returns Quecent (for float value it returns smaller one.
Example-
>>9//4
2

And
>>>-9/4=-2.25
>>>-9//4
-3(smaller than -2. 25)

Python modulo operator always return the remainder having the same sign as the divisor.

>>> -5 % 3
1
>>> 5 % -3
-1

>>>
-5 % 3 = (1 -2*3) % 3 = 1
5 % -3 = (-1 * -2*-3) % 3 = -1
Similarly
>>>-9%4=(3-4*3) %4=3

Hope it's clear now👍

Answer 2

// is floor division
-9//4 = -2.25 =-3
(-(9//4+1))
Here 9//4=2.25=2
So -(2+1)=-3
-3==-3

so here 2.25 is rounded to value smaller than it which is 2 because of floor division
but in -2.25 it is rounded to -3 as -3 is smaller than -2.25

and sorry I don't have any good explanation for (-9%4) ,but you have already got an answer from others

Answer 3

print((-9//4)==(-(9//4+1)) and (-9%4)==(4-9%4))

# -9//4 => -3
# -(9//4+1) => -(2+1) => -3
# -9%4 => 3
# 4-9%4 => 4-1 => 3
# print((-3 == -3) and (3 == 3)) => print(True and True) => print(True)

Answer 4

Lay_in_life thanks sir👍

Answer 5

𝐊𝐢𝐢𝐛𝐨 𝐆𝐡𝐚𝐲𝐚𝐥 you didn't explained how? As he can check the output by running it in code playground itself ,

Answer 6

Why is the third expression 3? 🤔

Answer 7

👍Clear now.🙂Thank you everyone!

Answer 8

𝐊𝐢𝐢𝐛𝐨 𝐆𝐡𝐚𝐲𝐚𝐥 thks

Answer 9

Please why -9//4=(-(9//4+1))

Answer 10

I think his doubts was
How (-9%4) =3
And no one is giving explanation about it,

Answer 11

Ok.thanks sir.

Answer 12

thanks again I will have a better way for a

Answer 13

Pada Oktober