ENH: Always do true division on Python 2.X
Close #5356.

Note: this version actually forces `a / b` to always do truediv as well. It's
less complicated to maintain if we do it that way, but it's also possible to
have this `a / b` use div and `a.div(b)` use truediv, just might be strange.
This is definitely different from numpy behavior.

We also may need to add the division future import to more places.

you can't just put the `from __future__ import division``in``pandas/__init.__py`` which AFAIK is always imported.
or is it module level somehow?
 It's module level :-/
 Just want to make it clear that this is the end result on Python 2.X without the future import (working interactively):

``` python
In [1]: import pandas as pd

In [2]: import numpy as np

In [3]: arr = np.array([1, 2, 3, 4])

In [4]: arr2 = np.array([5, 3, 2, 1])

In [5]: arr / arr2
Out[5]: array([0, 0, 1, 4])

In [6]: pd.Series(arr) / pd.Series(arr2)
Out[6]:
0    0.200000
1    0.666667
2    1.500000
3    4.000000
dtype: float64

In [7]:
```

Whereas before this PR:

``` python
In [2]: pd.Series(arr) / pd.Series(arr2)
Out[2]:
0    0
1    0
2    1
3    4
dtype: int64
```
 maybe make a separate section in v0.13 to highlite this (with an example like this)
 yep, just did that.

On Tue, Nov 5, 2013 at 7:16 AM, jreback notifications@github.com wrote:

> maybe make a separate section in v0.13 to highlite this (with an example
> like this)
> 
> —
> Reply to this email directly or view it on GitHubhttps://github.com/pydata/pandas/pull/5439#issuecomment-27768032
> .
 looks ok to me
