Clearly this is "wrong" (at least for scientific computing and arguably everywhere else) but here's why this happens. It's the difference in how the data types are defined - the output depends on the input types so
3/2=1 because 3 and 2 are int (integer) type so the output is a truncated integer. This is "floor division" and is how C does it too. However,
3.0/2=1.5 because 3.0 is a float so the output is a float even though 2 is still typed in as an int. I think it's actually a float now too but i'm not sure.
Starting with Python 2.2 a new division operator is introduced. Now
The "//" is now the floor division and the single "/" will be true division. I think Python 3 will have this completely integrated but all us 2.x users we're still SOL unless we want to rework all our codes.
Solution: import a module to overwrite the division sign with the upcoming (and computationally relevant) definition. At the very top include the statement
from __future__ import division
now the "/" will always be true division.
This module probably has a bunch of other important stuff. Since i'm learning python right before these all become standards is there a way to import ALL the future commands so I don't have to relearn anything when 3.x if viable for me? Something like from __future__ import * would be nice!