How is -6//4 equal to -2?

Question

Normally if i type
print(6//4)
the result is 1
But, >>>print (-6//4) gives me -2

Why and how does that happen?

Answer 1

This question is frequently asked and also anwered. You can read this:

https://stackoverflow.com/questions/37283786/floor-division-with-negative-number

Answer 2

I think it could be about modulo operator.

Because I assume that:
a % b = a - (a // b) * b

If we tested -6 % 4 with the formula:
-6 % 4 = -6 - (-6 // 4) * 4

If -6 // 4 was -1:
-6 - (-1) * 4 = -2

Then we would get -2 which is the wrong remainder.

If we always decided to take the lower whole number in case the result would not be a whole number.

Then we would assume that -6 // 4 = -2 and calculate the remainder again:
-6 - (-2) * 4 = 2

And this is the right remainder.

I think this would be good reason to make floor division always choose the lower whole number in case of not getting a whole number.

Answer 3

6/4 = 1.5

6//4 = 1 # floor division
-6//4 = -2 # floor value of -1.5

Answer 4

The floor is the largest integer less than or equal to the fractional result.

Answer 5

Since -1 is greater than -2 hence python prints -2 as python rounds the answer off to the nearest small digit

Answer 6

Basically // rounds down to the nearest integer.

6//4=1.5 ~ 1(not 2), as 1<2

-6//4=-1.5 ~ -2(not -1), as -2<-1

Answer 7

Its floor division. Round down the decimal result to next lower whole number.

Answer 8

Floor function = largest number less than the number.
-6/4 = -1.5 the floor function to -1.5 == -2 not -1 because -2<-1.5<-2. ..

Answer 9

print(6//1.5)