Python 2
round(3.5) => 4.0 round(4.5) => 5.0
Python 3
round(3.5) => 4 round(4.5) => 4
Mainly because:
- to take away the round-up bias.
- the result can be further divided by 2, and still an int
https://mathematica.stackexchange.com/questions/2116/why-round-to-even-integers
BrianChan.us 