Why -1//2 = -1 but int(-1/2) = 0?
Question:
I found that -1 // 2 is equal to -1 (Why not 0?), but int(-1 / 2) is equal to 0 (as I expected).
It’s not the case with 1 instead of -1, so both 1 // 2 and int(1 / 2) is equal to 0.
Why the results are different for -1?
Answers:
In Python, the division operator / and the floor division operator // have different behavior.
The division operator / returns a floating-point number that represents the exact quotient of the division. In the case of -1/2, the quotient is -0.5. When you cast it to int, it rounds the number up to 0.
The floor division operator // returns the quotient of the division rounded down to the nearest integer. In the case of -1//2, the quotient is -1, because -1 divided by 2 is -0.5, which is rounded down to -1.
That’s why -1//2 = -1 and int(-1/2) = 0 in python.
I found that -1 // 2 is equal to -1 (Why not 0?), but int(-1 / 2) is equal to 0 (as I expected).
It’s not the case with 1 instead of -1, so both 1 // 2 and int(1 / 2) is equal to 0.
Why the results are different for -1?
In Python, the division operator / and the floor division operator // have different behavior.
The division operator / returns a floating-point number that represents the exact quotient of the division. In the case of -1/2, the quotient is -0.5. When you cast it to int, it rounds the number up to 0.
The floor division operator // returns the quotient of the division rounded down to the nearest integer. In the case of -1//2, the quotient is -1, because -1 divided by 2 is -0.5, which is rounded down to -1.
That’s why -1//2 = -1 and int(-1/2) = 0 in python.