Question

>>> print(0.6//0.2)
2.0

WHY?!?

Answer 1

It's because of the way floats are stored internally. Because a mathematical float can have infinite precision, but, in real life, there's only so much memory to store one in, you get rounding errors.

The expression (0.6/0.2), single slash, actually evaluates to 2.9999999999999996, not 3.0 as you'd expect. You are also using the floor division operator I think so that's where it'll be going wrong. The swapped the operators round between Python2 and Python3, so what / or // do are the opposite in each series.

Answer 2

how did u know it evaluated to 2.99999999999996

Answer 3

It is explained here
http://docs.python.org/tutorial/floatingpoint.html

Answer 4

http://pastebin.com/vhM7Pcem

Answer 5

@seannn11
I just evaluated it interactively.