beacuse "sum" is reserved name for sum function. and we cant use reserved names if follow PEP8 rules.

why is sum not okay?

O(n) is good, but you can do better

see my solution :)

Maybe that's a C echoing in the authors head :)

I thought the same, but than I tested and noticed that if you input a negative number to the range function, it gives you always a 0. So the code also considers negative numbers

negative numbers are not considered in this code

approve

I don't think the parenthesis around the modulos are serving any purpose here. They can be removed

too long, and do not use "sum" for name of variable

nice!!!

since it is used as a variable I think it doesn't pose any problems here. But I still agree that this is not a good practice

I agree w/ @sine that a variable named 'sum' isn't wise. That withstanding, my solution was the same. This solution consistently runs about a half second faster than the higher voted one-liner with input of 100,000,000, and I'd argue it is easier to read.

here you redefine the sum() built-in function, which is usually a bad practice