BUG: Accept Generic Array-Like for .where
State: closed

Setup:
~~~python
>>> s = Series([1, 2, 3])
>>> cond = [False, True, True]
~~~
Before:
~~~python
>>> s.where(cond)
...
ValueError: where requires an ndarray like object for its condition
~~~
After:
~~~python
>>> s.where(cond)
0    NaN
1    2.0
2    3.0
dtype: float64
~~~

Note that `Index` objects can accept array-like objects as conditionals, and I wrote tests to confirm.

Labels:
name: Indexing
description: Related to indexing on series/frames, not to indexes themselves
name: Reshaping
description: Concat, Merge/Join, Stack/Unstack, Explode

Comments:
don't suppose there is an issue about this outstanding?
> don't suppose there is an issue about this outstanding?

No, there is not.  I just stumbled across this while grappling with the `NaN` in integer `Index`.
@jreback : The Appveyor build is broken for everybody due to `conda` conflicts.
> The Appveyor build is broken for everybody due to conda conflicts.

hmm, that's not friendly
I think the miniconda installer changed to 3.6.
> I think the miniconda installer changed to 3.6.

Yikes...though the installer website page doesn't seem to reflect that if that's true...
neah its not that. I had fixed the conda installer a while back at 4.2.15. So was installing the latest miniconda, but an incompat version of conda :<

switching to latest fixes. pushing soon.
ok rebase and windows should be good.
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@@            Coverage Diff             @@
##           master   #15414      +/-   ##
==========================================
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==========================================
  Files         136      136              
  Lines       49532    49540       +8     
==========================================
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| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/15414?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
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------

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thanks. I looked at the previous code and realize that ``inplace`` was being used similarly to how you are using it.
I think the alignment in ``.where`` is a mistake, but it probably is never used. We don't do alignment on boolean things anywhere else. So should remove this