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Division questions - Dionysis - Feb-13-2023
I'm new to Python and also refreshing my math...
I have two questions:
- Simple division (/) gives floats even if the result can be a round integer. Why is that? And how can I get a round integer instead of a .0 float? i.e. get the result 2/2=1 instead of 2/2=1.0 I'm not talking about integer division here, because when there is a decimal part I would like to see it. I.e. show a decimal part when it is not .0 Obviously this is relevant when dividing variables where the result is not know if will have a decimal part or not.
- In integer division (//) with one negative number, why is the result rounded down? i.e. why 10//-3=-4?
Thank you!
RE: Division questions - Larz60+ - Feb-13-2023
you can cast your results to integer:
int(10/2)
RE: Division questions - bowlofred - Feb-13-2023
Simple division always creates a float. You can check if the float is an integer and convert back if you would like.
quotient = 10 / 5
if quotient.is_integer():
quotient = int(quotient)
print(quotient)Floor division always rounds down. It doesn't round toward zero if that's what you're expecting.
RE: Division questions - deanhystad - Feb-13-2023
The documentation says
Quote:The / (division) and // (floor division) operators yield the quotient of their arguments. The numeric arguments are first converted to a common type. Division of integers yields a float, while floor division of integers results in an integer; the result is that of mathematical division with the ‘floor’ function applied to the result.
So division ( / ) returns a float because that is what it is supposed to do.
The same goes for your floor division question. The documentation says 10 // -3 == floor(10 / -3).
The documentation for floor says this:
Quote:math.floor(x)
Return the floor of x, the largest integer less than or equal to x. If x is not a float, delegates to x.__floor__, which should return an Integral value.
10 / -3 = -3.3333.... floor(-3.3333...) = -4
RE: Division questions - Larz60+ - Feb-14-2023
you can use floor division with double slashes '//' which rounds down
search fro floor division here: https://docs.python.org/3/reference/expressions.html
RE: Division questions - Dionysis - Feb-14-2023
(Feb-13-2023, 11:13 PM)bowlofred Wrote: Simple division always creates a float. You can check if the float is an integer and convert back if you would like.That's a nice way to do it!
quotient = 10 / 5 if quotient.is_integer(): quotient = int(quotient) print(quotient)
I'm still wondering though, why 4/2 couldn't just give an integer? Why a de facto float result was considered the best choice? After all, multiplication gives inetegers when it can... Why not division too?